Salary sacrifice car calculator — what it actually costs you
The headline saving minus the benefit-in-kind charge — the honest monthly cost of a salary sacrifice car, computed properly.
A salary sacrifice car trades gross salary for a leased company car. You save income tax and NI on the sacrificed amount, but pay benefit-in-kind tax on the car: P11D value × BiK rate × your tax rate. Petrol and diesel BiK rates run 15–37% in 2025/26, which claws back most of the saving — zero-emission cars pay just 3%, which is why EV schemes dominate. Enter your real quote above for the effective monthly cost.
- Personal allowance
- BiK 15–37% by CO2 (petrol/diesel)
- Applies in
- England, Scotland & Wales supported
- Calculation
- Sacrifice cuts tax + NI; BiK adds taxable benefit
The amount deducted from gross salary each month
List price incl. options — on the scheme quote
Parsed as: 1257L (£12,570 allowance, England & NI)
Why BiK makes or breaks the deal
Salary sacrifice saves you tax and NI on every pound of salary you give up — at basic rate that’s 28p per pound, at higher rate 42p. If that were the whole story, every sal-sac car would be a bargain. The benefit-in-kind charge is the other half: HMRC treats the car as income worth P11D × BiK%, and taxes it at your marginal rate through your tax code.
For a typical petrol car at 30% BiK, the charge often cancels two-thirds or more of the saving; for higher-rate taxpayers in high-CO2 cars it can exceed it. Zero-emission cars at 3% keep the charge tiny, which is why fleet EV schemes have exploded. The calculator above does both sides of the ledger with the engine that powers the rest of this site — no marketing gloss.
Questions people ask
Sources: Tax on company cars · National Minimum Wage rates