Car tax, officially known as Vehicle Excise Duty (VED), is a tax levied by the government on most vehicles used on public roads in the UK. The amount you pay is based on several factors, primarily your vehicle's CO2 emissions, fuel type, and its registration date. The system is designed to encourage the use of more environmentally friendly vehicles by taxing higher-emission cars more heavily.
How Car Tax is Calculated
The calculation of car tax has evolved over the years. For vehicles registered from April 1, 2017, the system is split into two parts for the first year and subsequent years:
First Year Rate: This is based on the vehicle's CO2 emissions. Cars with zero emissions pay £0. The rate increases significantly with higher CO2 emissions.
Standard Rate (from Year 2 onwards): For petrol and diesel cars, this rate is a flat fee, currently £180 per year (as of recent tax years). For alternative fuel vehicles (like hybrids), the standard rate is £170. Electric vehicles are currently exempt from this standard rate, paying £0.
Specific Tax Bands (Illustrative – subject to change by HMRC)
The first-year rate is determined by CO2 emissions bands. Here's a simplified illustration of how it might work for vehicles registered from April 1, 2017:
0 g/km: £0
1-50 g/km: £25 (for cars over £40,000, an additional supplement applies)
51-75 g/km: £100
76-90 g/km: £125
91-100 g/km: £145
101-110 g/km: £165
111-120 g/km: £185
121-130 g/km: £205
131-140 g/km: £225
141-150 g/km: £245
151-160 g/km: £265
161-170 g/km: £285
171-180 g/km: £305
181-190 g/km: £325
191-200 g/km: £345
201-225 g/km: £365
226-250 g/km: £405
Over 250 g/km: £450
Note: For cars with a list price of over £40,000 when new, an additional "expensive car supplement" of £390 is payable for five years (from the second year of registration onwards), meaning the total tax could be £570 (£180 + £390) or £560 (£170 + £390) for alternative fuel cars. This supplement applies from the second to the sixth year of registration.
Older Vehicles (Registered Before April 1, 2017)
For vehicles registered before April 1, 2017, the tax is based on CO2 emissions bands, which are different from the post-2017 system. The rates vary more widely and are generally lower for older, less efficient vehicles compared to the first-year rate of newer cars.
Electric Vehicles
Currently, zero-emission electric vehicles are exempt from both the first-year rate and the standard rate, meaning their annual car tax is £0.
Disclaimer
This calculator provides an *estimate* based on typical UK car tax rules for vehicles registered from April 1, 2017. Tax rules and rates can change annually. For the most accurate and up-to-date information, always consult the official UK government website (GOV.UK) or your local tax authority. This calculator does not account for specific regional variations or potential future changes in legislation.
function calculateCarTax() {
var vehicleValue = parseFloat(document.getElementById("vehicleValue").value);
var co2Emissions = parseFloat(document.getElementById("co2Emissions").value);
var fuelType = document.getElementById("fuelType").value;
var registrationYear = parseInt(document.getElementById("registrationYear").value);
var taxAmount = 0;
var expensiveCarSupplement = 0;
var isExpensiveCar = vehicleValue > 40000;
var currentYear = new Date().getFullYear();
var yearsSinceRegistration = currentYear – registrationYear;
// — Tax Calculation Logic —
if (isNaN(co2Emissions) || isNaN(registrationYear) || isNaN(vehicleValue)) {
document.getElementById("taxAmount").innerText = "Invalid input";
return;
}
// First Year Tax (based on CO2 emissions)
var firstYearTax = 0;
if (co2Emissions >= 0 && co2Emissions = 51 && co2Emissions = 76 && co2Emissions = 91 && co2Emissions = 101 && co2Emissions = 111 && co2Emissions = 121 && co2Emissions = 131 && co2Emissions = 141 && co2Emissions = 151 && co2Emissions = 161 && co2Emissions = 171 && co2Emissions = 181 && co2Emissions = 191 && co2Emissions = 201 && co2Emissions = 226 && co2Emissions 250) {
firstYearTax = 450;
}
// Apply expensive car supplement for the first year if applicable
if (isExpensiveCar && yearsSinceRegistration === 0) {
// The supplement is applied from the second year onwards, so not in the first year of registration.
// However, if the car is registered in the current year and is expensive, the first year tax is calculated normally.
// The supplement logic is handled below for subsequent years.
}
// Standard Rate (from Year 2 onwards)
var standardRate = 0;
if (fuelType === "petrol" || fuelType === "diesel") {
standardRate = 180;
} else if (fuelType === "hybrid") {
standardRate = 170;
} else if (fuelType === "electric") {
standardRate = 0; // Electric vehicles are currently exempt
}
// Expensive Car Supplement (applied from Year 2 to Year 6)
if (isExpensiveCar && yearsSinceRegistration >= 1 && yearsSinceRegistration <= 5) {
expensiveCarSupplement = 390;
}
// Determine total tax based on registration year
if (yearsSinceRegistration === 0) { // First year of registration
taxAmount = firstYearTax;
} else { // Subsequent years
taxAmount = standardRate + expensiveCarSupplement;
}
// Ensure tax is not negative (though unlikely with current rules)
taxAmount = Math.max(0, taxAmount);
document.getElementById("taxAmount").innerText = "£" + taxAmount.toFixed(2);
}