Best Free Car and Transport Calculators 2026 — EV vs Petrol, Fuel Cost, Buy vs Lease and CO2

Over a typical 5-year ownership period, electric cars are often cheaper despite higher purchase prices. Electricity costs roughly 3-5p per mile compared to 12-18p per mile for petrol. EVs have lower maintenance costs (no oil changes, fewer brake replacements) and lower insurance in some cases. From April 2025, EVs are subject to road tax (VED), but the rates remain lower than petrol and diesel vehicles. The breakeven point depends on annual mileage and how you charge.

Divide the journey distance by your car's fuel efficiency (miles per gallon or litres per 100km), then multiply by the fuel price per litre or gallon. For example, a 200-mile trip in a car doing 40 mpg at £1.40/litre: 200 / 40 = 5 gallons = 22.7 litres, so 22.7 x £1.40 = £31.82.

Buying is cheaper long-term if you keep the car for 5+ years and it holds its value. Leasing gives lower monthly payments, a new car every 2-3 years, and no depreciation risk, but you never own the car and face mileage limits and condition charges. The Buy vs Lease Calculator compares total cost over your chosen period.

A typical petrol car emits around 120-180g of CO2 per km. Multiply your annual mileage by your car's CO2 emissions rating (found in the V5C or on the manufacturer's spec sheet) to get your annual driving emissions. The CO2 Calculator does this automatically and compares your footprint to national averages.

On a standard home tariff of around 24p/kWh, a full charge for a 60kWh battery costs about £14.40 and gives roughly 200 miles of range. That works out to about 7p per mile. On an EV-specific overnight tariff (around 7-10p/kWh), the cost drops to about 2-3p per mile, making home charging significantly cheaper than petrol.

Compare cost per mile: divide your electricity cost per kWh by your EV's efficiency (miles per kWh), and divide your fuel cost per litre by your petrol car's efficiency (miles per litre). A typical EV does 3-4 miles per kWh; a typical petrol car does 7-9 miles per litre. The EV vs Petrol Calculator automates this with total cost of ownership over your chosen period.