Salary Sacrifice Car Calculator

How to use this calculator

1. Use the gross figure from the quoteScheme quotes normally show a gross sacrifice and a net cost. Enter the gross one here and check whether their net figure matches.
2. Get the P11D price rightIt is the list price including VAT, delivery and options — not what the scheme paid. Discounts do not reduce the benefit.
3. Check the BIK rate for the specific carPure electric cars carry the lowest rate. Plug-in hybrids depend on electric range, and anything petrol or diesel is many times higher.
4. Read the whole-term figure, not year oneThe benefit-in-kind rate rises annually. A three or four year term costs meaningfully more per month on average than the first year suggests.

Two opposing effects, netted off

A salary sacrifice car works by pulling one lever hard in your favour and one gently against you.

The lever in your favour is that the lease is paid from gross pay. A higher-rate taxpayer sacrificing £600 a month gives up only about £342 of take-home, because £258 would have gone in income tax and National Insurance anyway. That is a 43% discount before anything else happens.

The lever against you is the benefit in kind. Having a car available for private use is taxable, and the charge is a percentage of the list price set by emissions.

For a pure electric car that percentage is very low — a few per cent — which is the entire reason these schemes exist. Applying a low percentage to a list price produces a small taxable benefit and therefore a small tax bill.

Apply the same arithmetic to a petrol car and it collapses. A percentage several times higher against the same list price produces a benefit charge that swallows the sacrifice relief, which is why virtually every scheme on the market is electric-only.

What makes the comparison genuinely favourable is that the scheme price usually includes things a personal lease does not: insurance, servicing, tyres, breakdown cover and often the vehicle excise duty. Comparing the net monthly figure against a bare personal lease is comparing different products.

The complication is that the benefit-in-kind percentage rises every year. The schedule is published well ahead, and it has been climbing by a point a year. Over a three or four year term, that steadily erodes the advantage.

A quote showing only the year-one net cost is therefore flattering. The honest figure is the average across the term, and it is typically ten to twenty per cent higher than the headline.

And because the benefit is a share of list price rather than of what the car costs to lease, an expensive car with a cheap lease is taxed heavily and a cheap car with an expensive lease is taxed lightly. That relationship is worth checking against the specific quote rather than assuming.

Worked example: £600 a month on a £40,000 EV

On a £55,000 salary, sacrificing £7,200 a year takes the salary to £47,800.

That crosses a band boundary, and the effect is worth watching. The sacrificed £7,200 spans two rates: the £4,730 between £55,000 and the £50,270 upper earnings limit gets 40% tax plus 2% National Insurance, and the £2,470 below it gets 40% tax plus 8%.

Blended, the relief is 37.2%, so the sacrifice costs £4,521.80 of take-home rather than £7,200 — £376.82 a month.

Now the benefit in kind. £40,000 × 3% = £1,200 of taxable benefit. But the sacrifice has pushed total income to £49,000, which is below the higher-rate threshold, so the benefit is taxed at 20% rather than 40%: £240 a year, or £20 a month.

That is the same band crossing working in your favour on the second leg. It is a genuine feature of these schemes for anyone whose salary sits just above a threshold, and most quotes do not model it.

Net cost in year one: £396.82 a month against a £600 gross figure — about 66% of the headline.

Now run the term. With the BIK rate rising a point a year, year two at 4% costs £403.48 a month and year three at 5% costs £410.15. Averaged across 36 months the real cost is £403.48, and the total outlay is £14,525.40.

On a five-year term reaching 7%, the average rises to £410.15 a month. Anyone budgeting on the year-one figure across five years understates by around 3% — modest at this low BIK rate, and much larger on a car with a higher percentage or a bigger list price.

For a basic-rate taxpayer on £30,000 the arithmetic is worse. The relief is only 28%, so the same sacrifice costs £432 a month, and with £20 of benefit tax the net cost is £452 — £55 a month more than the higher earner pays for exactly the same car. Basic-rate employees get the least from these schemes, which is the opposite of what an employee benefit usually sets out to do.

And for anyone earning £110,000, the arithmetic is exceptional. Sacrificing out of the personal allowance taper gives 62% relief, so the sacrifice costs £228 a month. Even with the benefit taxed at 60%, adding £60 a month, the net cost is £288 — well under half the gross figure, and the cheapest position anyone can be in for one of these schemes.

Net cost by tax rate

The last row is why these schemes are electric-only. At a petrol car's benefit percentage the tax charge exceeds the sacrifice relief entirely, and the net cost is higher than the gross sacrifice — you would be better off leasing privately. The taper row is the opposite extreme, and it is the single most favourable position anyone can be in for one of these schemes.

The risks nobody puts in the quote

Early termination is the largest one. Leaving the employer normally counts as early termination of the lease, and the charge can run to several thousand pounds. Some schemes carry protection for redundancy; many do not, and resignation is almost never covered.

That makes a three or four year sacrifice car a meaningful constraint on changing jobs. It is worth reading the termination clause before the car, not after.

Sickness and maternity leave are the other common trigger. If pay drops below the point where the sacrifice can be made, the arrangement has to be funded some other way or terminated. Better schemes have a policy for this; ask what it is.

The reduced salary has the same consequences as any other sacrifice. Mortgage affordability is assessed on the lower figure, which for a £7,200 sacrifice can cost tens of thousands of borrowing capacity — considerably more than the car saves in a year.

Death in service cover, redundancy pay and pension contributions may all be calculated on the reduced salary unless the scheme protects them.

The minimum wage floor applies, which means these schemes are structurally unavailable to lower earners even though the cars are marketed as an employee benefit.

Mileage limits work as they do on any lease, with excess charges per mile at the end. Electric cars in particular attract people who then drive more than they expected because running costs are low, and the excess mileage charge can be a significant end-of-term bill.

On charging: the scheme covers the car, not the electricity. Home charging on an off-peak tariff is cheap; relying on public rapid charging is not, and can cost more per mile than a diesel. If you cannot charge at home, model the running cost before assuming the car is cheap to use.

Finally, the benefit-in-kind schedule beyond the published years is not fixed. The assumption of a point a year is reasonable but not guaranteed, and a faster rise would erode the advantage more quickly than this calculation shows.

Assumptions and limitations

• Benefit-in-kind percentages beyond the published schedule are an assumption, not a certainty
• Does not model early termination charges, which are the largest financial risk
• Assumes the sacrifice is affordable throughout — sickness and parental leave can disrupt it
• Does not include electricity, insurance excess or excess mileage charges
• Assumes the marginal rate stays constant across the term
• Does not check the National Minimum Wage floor, which is an absolute limit
• Not financial advice — read the scheme terms before committing to a multi-year arrangement

Questions people ask about this in United Kingdom