EV Fleet Conversion Calculator 2025/26
Calculate the cost and payback of switching your company fleet from petrol or diesel to electric vehicles in 2025/26. Model fuel savings, BIK tax benefits, OZEV grants and total cost of ownership across your fleet.
Key Inputs
- Fleet size (number of vehicles) and current fuel type (petrol/diesel)
- Average annual mileage per vehicle
- Current fuel cost (p/mile) — typical diesel van 14-18p/mile
- EV charging cost (p/kWh) — home/depot charging 7-25p; public rapid 40-80p
- EV energy consumption (kWh/100km) — typical EV van 25-35 kWh/100km
- Vehicle purchase premium: EV vs equivalent ICE (£)
- Available government grants: OZEV Workplace Charging Scheme (£350/socket)
What You'll Get
- Annual fuel saving per vehicle (£)
- Total annual fleet fuel saving (£)
- BIK tax saving for employee-benefit vehicles (3% EV vs 20-37% petrol in 2025/26)
- EV premium payback period (years)
- Annual CO2 reduction (tonnes)
- Total 5-year net saving vs ICE fleet (£)
Important Notes — 2025/26 Rates & Caveats
UK EV fleet BIK rates: fully electric cars 3% in 2025/26, rising to 4% in 2026/27 and 5% in 2027/28 — compared to 20-37% for petrol/diesel cars based on CO2 emissions. BIK saving makes EVs highly tax-efficient for employee benefit vehicles. OZEV Workplace Charging Scheme grants £350 per socket (maximum 40 sockets) for OZEV-approved installations — available to businesses, charities and public sector. Fuel cost comparison: at 25p/kWh charging and 25 kWh/100km, EV fuel cost is approximately 6.25p/mile vs 14-18p/mile for diesel — a 50-60% saving at typical 2025/26 prices.
Frequently Asked Questions
What is the BIK rate for electric company cars in 2025/26?
3% of list price in 2025/26, rising to 4% in 2026/27 and 5% in 2027/28 — compared to 20-37% for petrol cars based on CO2 emissions. For a higher-rate (40%) taxpaying employee in a £40,000 electric car, the income tax cost is just £480/year (3% × £40,000 × 40%). The same car on diesel (say 25% BIK) would cost £4,000/year — making EVs far more attractive as a benefit.
What grants are available for EV fleet charging?
Workplace Charging Scheme (WCS): £350 per socket (maximum 40 sockets) for OZEV-approved charge point installations; available to businesses, charities and public sector bodies. Electric Vehicle Infrastructure Grant for staff and fleets: up to £15,000 or 75% of installation cost for larger multi-socket installations in car parks. Applications are made through an OZEV-approved charge point installer.
Is it cheaper to fuel an electric fleet vs petrol?
At 25p/kWh charging and 25 kWh/100km energy use, EV fuel cost is approximately 6.25p/mile vs 14-18p/mile for petrol or diesel — a 50-60% saving at typical 2025/26 fuel prices. Home or depot overnight charging at 7-10p/kWh reduces EV running costs further to approximately 1.75-2.5p/mile. Public rapid charging (40-80p/kWh) can exceed diesel costs, so charging strategy is critical for fleet economics.
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