Fuel Benefit Calculator 2025/26

Q: How is fuel benefit tax calculated?

Fuel benefit tax = £27,800 × appropriate percentage (CO2-based) × your marginal tax rate. For example, a car with 120g/km CO2 (29% appropriate percentage) for a basic rate taxpayer: £27,800 × 29% × 20% = £1,612.40 annual tax.

Fuel Type

CO2 Emissions (g/km) Find this on your V5C or car manufacturer's website

Your Tax Rate

Months Fuel Provided

Appropriate Percentage

Taxable Benefit

Annual Tax

Monthly Cost

Is Free Fuel Worth It?

Annual Private Miles

Your Car's MPG

Fuel Price (pence/litre)

CO2 Emissions (g/km)

Your Tax Rate

Your Private Fuel Cost

Fuel Benefit Tax

Difference

Verdict

How to Avoid Fuel Benefit Tax

Option 1: Reimburse ALL Private Fuel

Pay your employer for every drop of private fuel used. Keep detailed records of private vs business mileage. This completely eliminates the fuel benefit charge.

Important: Partial reimbursement does NOT reduce the benefit!

If you only reimburse some of your private fuel, you'll still pay tax on the full fuel benefit. It's all or nothing.

Option 2: No Private Fuel Use

Only use the company car for business journeys. Use your own vehicle or other transport for private trips.

Option 3: Switch to Electric

Electric cars have just 2% appropriate percentage in 2025/26. Even with free electricity, the tax is minimal compared to petrol/diesel.

Fuel Benefit Comparison by Car Type

Car Type	CO2 Example	Appropriate %	Tax (Basic)	Tax (Higher)
Electric	0 g/km	2%	£111	£222
Plug-in Hybrid	50 g/km	12%	£667	£1,334
Efficient Petrol	100 g/km	25%	£1,390	£2,780
Average Petrol	130 g/km	32%	£1,779	£3,558
Large SUV	180 g/km	37%	£2,057	£4,114

2025/26 Tax Year

£27,800

Fuel Benefit Charge Multiplier

How Fuel Benefit Tax Works

If your employer provides free fuel for private use in a company car, you'll pay tax on a "fuel benefit". This applies even if you only use a small amount of private fuel.

Fuel Benefit Tax = £27,800 × Appropriate % × Your Tax Rate

Example: £27,800 × 29% × 20% = £1,612.40

The Appropriate Percentage

The same percentage used for company car tax (based on CO2 emissions) applies to fuel benefit. Lower emissions = lower percentage = less tax.

Key Points

The multiplier (£27,800) is the same regardless of actual fuel used
Even using £100 of private fuel triggers the full benefit
You must reimburse ALL private fuel to avoid the charge - partial doesn't count
The charge is proportional if fuel is only provided for part of the year

Appropriate Percentage Rates 2025/26

CO2 (g/km)	Electric	Hybrid (0-50km)	Petrol	Diesel
0	2%	2%	-	-
1-50	-	2-14%	-	-
51-54	-	15%	15%	19%
55-59	-	16%	16%	20%
60-64	-	17%	17%	21%
65-69	-	18%	18%	22%
70-74	-	19%	19%	23%
75-79	-	20%	20%	24%
80-84	-	21%	21%	25%
85-89	-	22%	22%	26%
90-94	-	23%	23%	27%
95-99	-	24%	24%	28%
100-104	-	25%	25%	29%
105-109	-	26%	26%	30%
110-114	-	27%	27%	31%
115-119	-	28%	28%	32%
120-124	-	29%	29%	33%
125-129	-	30%	30%	34%
130-134	-	31%	31%	35%
135-139	-	32%	32%	36%
140-144	-	33%	33%	37%
145-149	-	34%	34%	37%
150-154	-	35%	35%	37%
155-159	-	36%	36%	37%
160+	-	37%	37%	37%

Note: Diesel adds 4% unless RDE2 compliant. Maximum 37%.

Frequently Asked Questions

What is the fuel benefit multiplier for 2025/26?

The fuel benefit multiplier for 2025/26 is £27,800. This is multiplied by the car's appropriate percentage (based on CO2 emissions) to calculate the taxable fuel benefit.

How is fuel benefit tax calculated?

Fuel benefit tax = £27,800 x appropriate percentage (CO2-based) x your marginal tax rate. For example, a car with 120g/km CO2 (29% appropriate percentage) for a basic rate taxpayer: £27,800 x 29% x 20% = £1,612.40 annual tax.

Can I avoid fuel benefit tax?

Yes, there are three ways: 1) Reimburse your employer for ALL private fuel used, 2) Only use the company car for business journeys, or 3) Choose an electric company car (2% appropriate percentage in 2025/26). Partial reimbursement does NOT reduce the benefit.

Is fuel benefit worth it?

Often no - fuel benefit is only worthwhile if you do substantial private mileage. Many employees find it cheaper to pay for their own private fuel. Use our calculator to compare the tax cost against your actual private fuel spend.

Do electric cars have a fuel benefit charge?

Electric cars still technically attract a fuel benefit charge if free electricity is provided, but since the appropriate percentage is 2% in 2025/26, the tax is minimal - typically under £115/year for higher rate taxpayers.

What if fuel is only provided for part of the year?

The fuel benefit is proportionally reduced. If free fuel is provided for 6 months, you pay tax on 6/12 (50%) of the full benefit.

Does the amount of private fuel used affect the tax?

No - whether you use £50 or £5,000 of private fuel, the tax is the same. The benefit is calculated using the £27,800 multiplier regardless of actual consumption.

When Fuel Benefit Makes Sense

Free fuel might be worthwhile if:

You drive very high private mileage (typically 15,000+ miles/year)
You have a large, inefficient vehicle with high fuel costs
Fuel prices are very high
You're a basic rate taxpayer (lower tax bill)

Break-Even Point

To find if it's worth it, calculate:

Break-even private miles = (Fuel Benefit Tax) ÷ (Cost per mile)

Example: £1,612 ÷ £0.16/mile = 10,075 private miles

If you drive fewer private miles than the break-even, pay for your own fuel.

Pro Tips for Accurate Results

Double-check your input values before calculating
Use the correct unit format (metric or imperial)
For complex calculations, break them into smaller steps
Bookmark this page for quick future access

Understanding Your Results

Our Fuel Benefit Calculator provides:

Instant calculations - Results appear immediately
Accurate formulas - Based on official UK standards
Clear explanations - Understand how results are derived
2025/26 updated - Using current rates and regulations

Common Questions

Is this calculator free?

Yes, all our calculators are 100% free to use with no registration required.

Are the results accurate?

Our calculators use verified formulas and are regularly updated for accuracy.

Can I use this on mobile?

Yes, all calculators are fully responsive and work on any device.