Every input named and dated

What a car costs to run in a year

Five lines make up almost all of it, and one of them moves so much with your own circumstances that no page can tell you what it will be. Here is the whole calculation with the working shown, so you can swap your own figures in where ours do not fit.

7,100 miles a yearUnleaded 161.61p a litreDiesel 183.49p a litre28 cited sources

£2,311A year on the family hatchback worked below

£193The same figure a month

16.93pFuel cost per mile, petrol

26.11pHome electricity, per kWh

Most running cost calculators are built backwards. They start with a round mileage nobody drives, add a fuel economy figure taken from a laboratory, and quote an insurance premium that describes nobody in particular. The number that comes out looks authoritative and is almost impossible to check. Everything on this page is the other way round: each input names the publication it came from and the date it applies from, and the arithmetic joining them is written next to the result.

The mileage matters most, because two lines scale with it and three do not. At 7,100 miles a year, the average for a car in England, fuel is the largest single line but it is not the majority of the bill. Drive twice that and fuel dominates everything else. Drive half of it and the fixed lines, tax, insurance, the service and the test, become the story. Before you compare two cars, work out which of those two situations you are in, because it changes which car is cheaper.

Depreciation sits apart from the rest and is usually the biggest number of all on a newer car. It is not a bill that arrives, which is exactly why it gets left out of these comparisons, and it is shown separately at the foot of this page rather than folded into a single headline figure that would hide it.

Pump prices

What fuel costs now, and what it has done for two years

The Department for Energy Security and Net Zero publishes a UK average every week. Petrol and diesel are kept apart here because blending them into one number would have been wrong for almost everybody in the last eighteen months.

Week commencing 31 August 2026

Current average pump prices

Unleaded petrolUK average, 31 August 2026: 161.61p
DieselUK average, 31 August 2026: 183.49p
Home electricityPrice cap unit rate, standard variable tariff by direct debit: 26.11p a kWh

Diesel is 21.88p a litre dearer than unleaded this week. On a fifty litre fill that is £10.94 more every time, which is the figure to hold in your head against the extra miles per gallon a diesel gives you.

Source: Department for Energy Security and Net Zero, Weekly road fuel prices

Two year range

The spread you are living in

Unleaded, lowest month: 131.60p
Unleaded, highest month: 157.45p
Diesel, lowest month: 138.49p
Diesel, highest monthApril 2026: 189.99p

Diesel moved 51.50p a litre between its cheapest and dearest month in this series, against 25.85p for unleaded. Anyone budgeting a diesel on a figure more than a few months old is budgeting on the wrong number.

Monthly average UK pump prices in pence per litre for unleaded petrol and diesel over the last two years
Month	Unleaded	Diesel	Gap
July 2026	152.19p	167.59p	15.40p
June 2026	155.30p	176.44p	21.14p
May 2026	157.45p	187.14p	29.69p
April 2026	156.86p	189.99p	33.13p
March 2026	140.21p	158.67p	18.46p
February 2026	131.60p	141.12p	9.52p
January 2026	133.24p	142.47p	9.23p
December 2025	136.34p	145.72p	9.38p
November 2025	135.04p	143.82p	8.78p
October 2025	134.66p	142.77p	8.11p
September 2025	133.98p	141.84p	7.86p
August 2025	134.22p	142.18p	7.96p
July 2025	133.87p	141.38p	7.51p
June 2025	131.89p	138.49p	6.60p
May 2025	132.39p	139.05p	6.66p
April 2025	134.55p	141.69p	7.14p
March 2025	137.50p	144.83p	7.33p
February 2025	139.15p	146.42p	7.27p
January 2025	137.11p	144.12p	7.01p
December 2024	136.29p	142.61p	6.32p
November 2024	134.81p	140.47p	5.66p
October 2024	133.96p	139.13p	5.17p
September 2024	136.80p	141.81p	5.01p
August 2024	142.32p	147.79p	5.47p

Newest month first. Each month is the unweighted mean of that month's published weeks. The latest complete month is July 2026.

Source: Department for Energy Security and Net Zero, Weekly road fuel prices

Two years of monthly averages is here rather than a single current price because one week tells you nothing about what a year will cost. Read down the diesel column and the series does something unusual in the spring of 2026: after eighteen months of drifting within a few pence, it steps up sharply over two months and then comes back down more slowly than it went up. We have no sourced explanation for why, so none is offered. What the shape does tell you is that the gap between the two fuels is not a fixed property of diesel, and a rule of thumb about which fuel is cheaper that was formed a year ago is not safe to reuse.

For budgeting, the useful figure is not this week's price but the range. If you plan a diesel around its cheapest month in this series and it returns to its dearest, the fuel line moves by more than the entire annual cost of taxing and testing the car. Planning around the middle of the range and treating the rest as variance is a more honest way to compare two cars than picking whichever price was published on the day you looked.

Real world economy, not the lab figure

Cost per mile by segment

Every mpg figure here is what owners of a named car actually recorded, not what the type approval test produced. The gap between the two runs to a fifth in the worst segment, and a calculator built on lab figures is wrong by that much before it starts.

Fuel and energy cost per mile by car segment for petrol, diesel and electric, with the real world economy each is worked from
Segment	Petrol mpg	Petrol per mile	Diesel mpg	Diesel per mile	Miles per kWh	Electric per mile
City car	48.9	15.02p	55.3	15.08p	3.9	6.69p
Supermini	45.1	16.29p	62.2	13.41p	4	6.53p
Family hatchback	43.4	16.93p	54.7	15.25p	3.7	7.06p
Estate	42.2	17.41p	53.6	15.56p	3.6	7.25p
Medium SUV	38.8	18.94p	53.5	15.59p	3.6	7.25p
Large SUV	35.6	20.64p	45.4	18.37p	2.9	9.00p
Executive saloon	40.9	17.96p	52.2	15.98p	4	6.53p

Pence per mile is the pump price per litre multiplied by 4.54609 litres in an imperial gallon and divided by the mpg figure. The electric column is the home electricity unit rate divided by miles per kWh, so it is the cost of charging at home on a standard tariff and nothing else.

Sources: Honest John, Real MPG: Hyundai i10 (2019 on); Honest John, Real MPG: Fiat 500 (2008 to 2025); Honest John, Real MPG: Ford Fiesta (2017 to 2023); Honest John, Real MPG: Ford Focus (2018 to 2025); Department for Energy Security and Net Zero, Weekly road fuel prices

Family hatchback, 7,100 miles

The three fuels side by side

16.93p

Petrol, per mile

£1,202

15.25p

Diesel, per mile

£1,083

7.06p

Electric at home, per mile

£501

Fuel and energy cost per mile for a family hatchback, with the annual cost at 7,100 miles beside each. The dearest per mile sits highest.
Category	Share	Value
Petrol, per mile	16.93p	£1,202
Diesel, per mile	15.25p	£1,083
Electric at home, per mile	7.06p	£501

Charging at home is the cheapest way to move a car on this page by a wide margin, and it is the only figure here that depends on having somewhere to plug in. Rapid charging on the public network costs several times the home rate, so an electric car without a driveway or a workplace charger does not deliver the number in that column. The assumptions section below states the public network figures the dataset carries.

Diesel closes most of its pump price disadvantage through economy, and in a large SUV it comes out clearly ahead because weight punishes a petrol engine far more than a diesel one. In a supermini the diesel advantage is large on paper and irrelevant in practice, because almost nobody sells one and the ones that exist are old enough that a clean air zone charge matters more than pence per mile.

These are per mile figures, so they compare cars, not owners. The dataset notes that petrol cars average 6,200 miles a year, diesels 8,300 and battery electric cars 8,900. A diesel that costs less per mile and covers a third more miles does not produce a smaller fuel bill.

Which cars each segment figure comes from

City car
Petrol is the Hyundai i10 1.0 MPI at 48.9mpg, 91 per cent of its official WLTP figure, so about 9 per cent short. Diesel city cars stopped being sold years ago, so the diesel number is a used Fiat 500 1.3 MultiJet at 55.3mpg, 82 per cent of the official figure it was sold on. Electric is the Fiat 500e 42kWh at 3.9 miles per kWh.
Supermini
Petrol is the Ford Fiesta 1.0T EcoBoost 100 at 45.1mpg and diesel the Fiesta 1.5 TDCi 85 at 62.2mpg. Both land within about 5 per cent of their official WLTP figures, which is as close as any segment gets. Electric is the Vauxhall Corsa Electric 51kWh at 4.0 miles per kWh.
Family hatchback
Petrol is the Ford Focus 1.0 EcoBoost 125 at 43.4mpg against an official 52.3mpg, and diesel the Focus 1.5 TDCi 120 at 54.7mpg against 67.3mpg. Both sit roughly a fifth under the lab figure, the widest gap of any segment here, because small turbocharged engines work hardest in a car this size. Electric is the Volkswagen ID.3 Pro at 3.7 miles per kWh.
Estate
Petrol is the Ford Focus Estate 1.0 EcoBoost 125 at 42.2mpg, 90 per cent of official, and diesel the same car with the 1.5 TDCi 120 at 53.6mpg, 83 per cent of official. Expect 10 to 17 per cent under the printed figure. Electric is the MG5 EV Long Range at 3.6 miles per kWh.
Medium SUV
Petrol is the Nissan Qashqai 1.3 DIG-T 140 at 38.8mpg, within 3 per cent of its official WLTP figure. Diesel is the Qashqai 1.5 dCi at 53.5mpg, 86 per cent of the official figure it was sold on. Electric is the Kia Niro EV at 3.6 miles per kWh.
Large SUV
Petrol is the Skoda Kodiaq 1.5 TSI 150 at 35.6mpg, about 19 per cent under official, and diesel the Kodiaq 2.0 TDI 150 DSG at 45.4mpg, about 12 per cent under. Weight and frontal area punish the petrol engine more than the diesel. Electric is the Kia EV9 99.8kWh rear-wheel drive at 2.9 miles per kWh, the thirstiest electric car in this table by a wide margin.
Executive saloon
Petrol is the BMW 320i automatic at 40.9mpg, 96 per cent of official, and diesel the 320d at 52.2mpg, 92 per cent of official. Bigger engines in slippery bodies get closer to their lab figures than small ones in tall bodies do. Electric is the BMW i4 eDrive40 at 4.0 miles per kWh.

Family hatchback, petrol, 7,100 miles

The annual bill, line by line

One worked example, with the assumption behind every line printed beside it. Change any input and the total changes with it, which is the point of showing the lines rather than a single figure.

Annual running cost lines for a family hatchback petrol car covering 7,100 miles a year
Cost line	A year	A month	Share
FuelFamily hatchback petrol at 43.4 mpg, 7,100 miles	£1,201.92	£100.16	52%
Vehicle taxFlat standard rate for the 2026/27 tax year	£200.00	£16.67	9%
InsuranceMedian of the seven published age bands. An index average, not a quote	£699.00	£58.25	30%
ServicingOne interim service one year, one full service the next	£210.00	£17.50	9%
TotalBefore depreciation, tyres, repairs and parking	£2,311	£193	100%

How the bill splits

52%

Fuel

30%

Insurance

Share of the annual running cost total taken by each line for a family hatchback petrol car
Category	Share
Fuel	52%
Vehicle tax	9%
Insurance	30%
Servicing	9%

Read this before the total

Insurance is the line to distrust

Insurance varies more by individual circumstance than any other line on this page, and by more than the choice of car does. The figure used above is the median of the seven published age bands. It is an index average of prices quoted, not a quote, and it is not a prediction of what you will pay.

Average car insurance premium by age band, from a published price index
Age band	Average quoted
17 to 20	£1,813
20 to 29	£1,255
30 to 39	£850
40 to 49	£699
50 to 59	£552
60 to 69	£459
70 and over	£482

The band highlighted is the median, which is the figure the total above uses. Swap in your own band and the total moves with it.

Not in the total

What this leaves out

Tyres, brake pads and discs, a cambelt, brake fluid and coolant changes, and anything found on the ramp.
Depreciation, which is shown on its own below because it usually dwarfs everything in the table.
Parking, permits, tolls, and any clean air zone or congestion charge, which depend entirely on where you drive.
Finance interest, if the car is on a loan or a monthly agreement.

Check the charging zones

Read the split rather than the total. On this worked example fuel is the largest line and insurance is close behind it, while the three certain, fixed, unavoidable costs, tax, the service and the test, come to less than either. That is the shape of an average mileage petrol car. A high mileage diesel tips heavily towards fuel, and a young driver's first car tips so far towards insurance that nothing else in the table matters much.

The tax line here is the flat standard rate for a car in the current regime past its first licence. A car registered between March 2001 and March 2017 pays its CO2 band instead, which can be well above or well below this figure, and a car carrying the expensive car supplement pays considerably more. The tax rates page has every band if the car you are looking at is not in the simple case.

The cost that never sends an invoice

Depreciation, as a share of what you paid

On a car bought new this is the largest running cost by a distance, and because it is only realised on the day you sell, it is the one almost every comparison quietly omits.

Retained value as a share of the original price by years owned, with the equivalent cash figure per ten thousand pounds of purchase price
Years owned	Value retained	Lost that year	Per £10,000 paid
After 1 year	75%	25 points	£7,500
After 2 years	60%	15 points	£6,000
After 3 years	45%	15 points	£4,500
After 4 years	39%	6 points	£3,900
After 5 years	34%	5 points	£3,400
After 6 years	30%	4 points	£3,000
After 7 years	26%	4 points	£2,600
After 8 years	23%	3 points	£2,300

The final column is the retained percentage applied to £10,000 of purchase price, so multiply it by your own price in units of ten thousand. It is a market average and not a valuation of any particular car.

Sources: Autotrader, Car depreciation explained; Carwow, How much do cars depreciate per year?; Autotrader, Used car market enters 2026 with positive momentum as 2025 sales finish 2% ahead of previous year; Autotrader, Autotrader Retail Price Index, April 2026

This is a market average, not a valuation. Two cars of the same age and mileage can be 20 percentage points apart on retained value.
Segment matters. Small cars and popular family hatchbacks hold on best in percentage terms because there is always someone shopping for one. Large executive saloons and big petrol SUVs fall hardest, and a car in an unpopular colour or an odd specification falls harder still.
Fuel type matters too, and it has been moving. Used electric prices were down 7.4 per cent year on year in December 2025, at an average of £24,029, while used petrol was up 1.5 per cent and used diesel up 2.5 per cent. Anyone who bought an electric car new in 2022 or 2023 has taken a bigger hit than a petrol owner did.
That gap is narrowing. By April 2026 the average used electric car was £23,555 and rising month on month while petrol and diesel prices softened, and three to five year old electric cars were selling at the same money as petrol equivalents. The steepest part of the electric slide looks to be behind the market, though it is still visible in the resale price of a three year old car.
Years one to three come straight from the published rule. Years four to eight apply the published later-life rate to the value still in the car, so treat the tail of the curve as a shape rather than a quote.
Mileage and history change the answer more than age alone. A well documented 60,000 mile car will beat a patchy 30,000 mile one on the forecourt more often than not.

The practical use of a curve like this is not predicting a sale price. It is seeing where the steep part is, and then buying on the other side of it. A three year old car has already had the worst of its depreciation taken by somebody else, which is why the same money buys so much more car at three years old than at one. From about year four the percentage loss is applied to a much smaller number, so the cash loss each year shrinks even though the rate does not.

Against that, the running costs in the table above tend to rise as a car ages, because a service on an older car turns up more work and wear items start arriving together. Somewhere in the middle of the curve is the cheapest total cost of ownership, and for most ordinary cars it sits several years further along than people expect.

Nothing hidden

Every assumption, stated

These are the notes shipped with the data rather than written for this page, so they stay attached to the figures they qualify. If one of them does not describe you, the line it feeds is the line to change.

Inputs used above

Annual mileage: 7,100 miles
Unleaded petrol: 161.61p a litre
Diesel: 183.49p a litre
Home electricity: 26.11p a kWh
Servicing: £210.00
Vehicle taxStandard rate, 2026/27: £200
InsuranceMedian of the published age bands: £699
Litres in a gallonThe imperial gallon, used to turn mpg into pence per mile: 4.54609

Mileage: 7,100 miles a year is the average for all cars in England in 2024. Petrol cars averaged 6,200 miles, diesels 8,300 and battery electric cars 8,900, so if you are looking at a diesel or an electric car expect the fuel or charging line to be bigger than the average suggests.

Pump prices are the UK average for the week commencing 31 August 2026: 161.61p a litre for unleaded and 183.49p for diesel. Both include fuel duty of 52.95p a litre and VAT at 20 per cent. DESNZ dates each figure by the Monday the survey week begins, so it is a week commencing date rather than a week ending one.

Petrol and diesel are kept apart on purpose. Between February and April 2026 the monthly average diesel price went from 141.12p to 189.99p a litre while unleaded went from 131.60p to 156.86p. A single blended fuel price would have been wrong for almost everybody during those months.

Electricity: 26.11p a kWh is the Ofgem price cap unit rate for a standard variable tariff paid by direct debit, averaged across England, Scotland and Wales, for 1 July to 30 September 2026. The 57.19p daily standing charge is left out because you pay it whether you own a car or not.

Charging away from home costs a great deal more. Zapmap put the weighted average pay-as-you-go price at 54p a kWh on chargers up to 49kW and 79p a kWh on chargers of 50kW and above in June 2026. At 79p, a rapid charge is about three times the price of the same energy at home, which is the main reason two owners of the same electric car report such different costs.

Electric figures elsewhere in this model are miles per kWh taken from the battery. Your meter will record a little more than that, because some energy is lost in charging, so treat miles per kWh as the car's number rather than the bill's.

Insurance moves more with your own circumstances than any other line here. Postcode, claims history, job, how far you drive, the exact trim and where the car sits overnight all shift the price more than the choice of car does. These are index averages of prices quoted in May 2026, not quotes, and your own figure can sit well either side of them.

Two insurance numbers are worth holding side by side. The index above tracks prices quoted and put the overall average at £719. The ABI tracks prices actually paid and put the average comprehensive premium at £560 in the first quarter of 2026. They answer different questions, so do not read a gap between them as one of them being wrong.

Servicing: £210 a year assumes a car alternating an interim service one year and a full service the next, at published fixed prices of £179.99 and £239.99 in July 2026. It covers the service itself only. Brake fluid and coolant changes, a cambelt, tyres, and anything found while the car is on the ramp are extra.

The vehicle tax figure is the only input on this page taken from a different dataset, the vehicle excise duty rate tables, and it assumes a car in the post 2017 regime that is past its first licence and not carrying the expensive car supplement.

Every figure, traced

Where these numbers come from

Grouped by what each one backs. The economy list is long because a segment average that cannot name its cars is not checkable, so every model behind every mpg figure is cited individually.

Prices and assumptions

Department for Energy Security and Net Zero
Weekly road fuel prices
As of 31 August 2026
Ofgem
Energy price cap unit rates and standing charges
As of 1 July 2026
Ofgem
Changes to energy price cap between 1 July and 30 September 2026
As of 1 July 2026
Zapmap
Zapmap Price Index: average weighted price to charge on the public network
As of 1 June 2026
Confused.com with WTW
Car insurance price index: average car insurance cost by age
As of 1 May 2026
Association of British Insurers
Motor premiums remain stable, but cost of repairs still high
As of 30 April 2026
Halfords
Interim Service, published fixed price
As of 30 July 2026
Halfords
Full Service, published fixed price
As of 30 July 2026
Department for Transport
National Travel Survey table NTS0901: annual mileage of cars by ownership, fuel type and trip purpose, England
As of 27 August 2025

Fuel price history

Department for Energy Security and Net Zero
Weekly road fuel prices
As of 31 August 2026

Economy by segment

Honest John
Real MPG: Hyundai i10 (2019 on)
As of 30 July 2026
Honest John
Real MPG: Fiat 500 (2008 to 2025)
As of 30 July 2026
Honest John
Real MPG: Ford Fiesta (2017 to 2023)
As of 30 July 2026
Honest John
Real MPG: Ford Focus (2018 to 2025)
As of 30 July 2026
Honest John
Real MPG: Ford Focus Estate (2018 to 2025)
As of 30 July 2026
Honest John
Real MPG: Nissan Qashqai (2013 to 2021)
As of 30 July 2026
Honest John
Real MPG: Skoda Kodiaq (2016 to 2024)
As of 30 July 2026
Honest John
Real MPG: BMW 3 Series (2018 on)
As of 30 July 2026
EV Database
Fiat 500e Hatchback 42 kWh
As of 30 July 2026
EV Database
Vauxhall Corsa Electric 51 kWh
As of 30 July 2026
EV Database
Volkswagen ID.3 Pro
As of 30 July 2026
EV Database
MG MG5 EV Long Range
As of 30 July 2026
EV Database
Kia Niro EV
As of 30 July 2026
EV Database
Kia EV9 99.8 kWh RWD
As of 30 July 2026
EV Database
BMW i4 eDrive40
As of 30 July 2026

Depreciation

Autotrader
Car depreciation explained
As of 6 October 2023
Carwow
How much do cars depreciate per year?
As of 17 January 2025
Autotrader
Used car market enters 2026 with positive momentum as 2025 sales finish 2% ahead of previous year
As of 8 January 2026
Autotrader
Autotrader Retail Price Index, April 2026
As of 8 May 2026

Straight answers

Common questions about running costs

Why is your fuel figure lower than other calculators?

Because the mileage is the real average rather than a round number. The Department for Transport puts the average car in England at 7,100 miles a year, and most calculators assume 10,000 or 12,000. If you drive more than the average, scale the fuel line up in proportion, because it is the one line on this page that moves exactly with mileage.

Can I treat the insurance figure as a quote?

No, and it is the one line here you should not plan around. Insurance moves more with your own circumstances than with the car: postcode, claims history, job, annual mileage, the exact trim and where the car sits overnight all shift the price more than the choice of model does. The figures on this page are index averages of prices quoted, published by age band. Your own number can sit well either side of them.

Is a diesel still cheaper to run?

On fuel alone it depends on the pump gap. Diesel does more miles per gallon in every segment here, but it has been the dearer fuel per litre by a wide margin, so the pence per mile advantage is much smaller than the mpg difference suggests and in some months it disappears. Diesels also average more miles a year, which multiplies whatever the pence per mile figure turns out to be.

Why is depreciation shown as a percentage rather than in pounds?

Because a cash figure needs a purchase price, and only you know what you are about to pay. The curve here is retained value as a share of the original price, with a column showing what that means for every ten thousand pounds of it. Multiply the percentage by your own price and you have your own number.

Does this include tyres, brakes and repairs?

No. The servicing line covers the scheduled service only. Tyres, brake pads and discs, a cambelt, brake fluid and coolant changes, and anything found while the car is on the ramp all sit outside it. Those are the costs that separate a cheap year from an expensive one, and they are better estimated per job than averaged across a year.

Work out one car's tax Every road tax band Typical repair prices