Salary sacrifice car calculator: the net monthly cost, worked out.

Most people searching for a salary sacrifice car calculator want one number: what an electric car actually costs them each month after the tax and National Insurance savings. This page shows how that number is built, works through real examples across all three tax bands, and then lets you model your own car in about 20 seconds.

How salary sacrifice car pricing works

Salary sacrifice lets an employee give up part of their gross salary in exchange for an electric car. Because the sacrifice comes out of pay before tax, the employee stops paying income tax and employee National Insurance on that slice of salary. That is where the saving comes from. Set against it is a small Benefit-in-Kind (BIK) tax charge, because the car is a taxable benefit.

The net monthly cost is, in plain terms:

Gross monthly sacrifice, minus the income tax saved, minus the employee National Insurance saved, plus the BIK tax due. The result is the figure that actually leaves your take-home pay.

Four things move that number: your marginal tax band (20% basic, 40% higher, 45% additional), the car and its P11D value, the contract term and mileage, and the BIK rate for the year. For a fully electric company car the BIK rate is 4% for 2026/27, rising incrementally to 5% in 2027/28, 7% in 2028/29 and 9% in 2029/30. Even at 9% an EV stays far below the 20% to 39% bands that petrol and diesel cars sit in, which is why the saving holds up over a typical term.

Worked examples: net monthly cost by tax band

These are real configurations modelled on the 2026/27 position. The car figure is the salary sacrifice cost of the vehicle alone. The bundle figure adds home-energy items (charger, solar or battery) through the same single payroll line. Figures are indicative and depend on individual circumstances.

Basic rate (20%): Kia EV3 148kW Air 58.3kWh, 48 months

Car alone: £354.74 a month. Add a charger, solar and battery: £419.00 a month. Combined with the full home-energy bundle: £773.74 a month.

Higher rate (40%): Tesla Model Y RWD, 36 months

Car alone: £432.46 a month. Add solar and battery: £495.14 a month. Combined: £927.60 a month. The higher the marginal rate, the larger the tax and NI saving on the sacrificed salary, which is why higher-rate taxpayers tend to see the strongest net position.

Additional rate (45%): Škoda Enyaq 85 SE L, 36 months

Car alone: £403.86 a month. Add a charger and battery: £327.75 a month. Combined: £731.61 a month.

The full breakdown behind these bundles, including how the home-energy items are priced alongside the car, is in our guide to the EV salary sacrifice and home energy bundle.

Model your own car

The examples above are a starting point. To get the figure for your car, your tax band, your term and your mileage, use the full Perx calculator. It covers both views: the employee view returns an indicative net monthly cost for a chosen car, and the employer view models the indicative employer National Insurance effect across your headcount. No sign-up, no file upload, no call before you see a number.

Because Orbis intelligence is included with every Perx car, the scheme you model is one the scheme owner can see in operation once it runs: live mileage against the contracted allowance, and the vehicle's real-world condition, from day one. Read more in our guide to what fleet intelligence is, or see how the scheme comes together on the Perx page.

Figures are indicative and depend on individual circumstances: salary, tax position, vehicle, term and mileage all change the outcome. This page is general information, not tax or financial advice.

Frequently asked questions

How much does a salary sacrifice car cost per month?

It depends on the car, your tax band, the term and the mileage, but a worked example gives the shape: a Kia EV3 Air over 48 months is around £354.74 a month for a basic-rate taxpayer, on the 2026/27 Benefit-in-Kind position. Higher-rate and additional-rate taxpayers usually see a stronger net position because the income tax and National Insurance saved on the sacrificed salary is larger. The calculator returns an indicative net monthly cost for your specific car and tax band; it is not personal tax advice.

How is the net monthly cost of a salary sacrifice car calculated?

The net monthly cost is the gross monthly salary sacrificed, minus the income tax saved on it, minus the employee National Insurance saved on it, plus the Benefit-in-Kind tax due on the car. For a fully electric car the BIK rate is 4% for 2026/27, so the added tax is small relative to the tax and NI saved, which is what makes the net figure attractive. The result is indicative and depends on your individual circumstances.

What is the Benefit-in-Kind rate for electric cars in 2026/27?

For fully electric company cars the Benefit-in-Kind rate is 4% for 2026/27, rising to 5% in 2027/28, 7% in 2028/29 and 9% in 2029/30. Even at the top of that range an EV stays well below the 20% to 39% bands that petrol and diesel cars fall into, so the salary sacrifice saving holds up across a typical three or four year term.

Can I include home energy in a salary sacrifice scheme?

Yes. The Perx bundle covers four components through one payroll line: an electric car, a home charger, solar and a home battery. Each can be included or excluded independently, so the calculator can model the car alone or the car plus any combination of home-energy items. The worked examples above show both the car-only and the bundled figure for each tax band.