Car Annual Running Cost Calculator

The True Cost of Car Ownership

The monthly finance payment is the number people quote, and it is rarely the number they actually spend. At this calculator's defaults, a 28,000 car with 5,000 down, financed at 7% over five years, plus 120 a month of insurance and 150 a month of fuel, the repayment is 455.43 while the all-in monthly figure is 808.76. Across the five years that comes to 48,525.65: 5,000 paid upfront, 27,325.65 in loan repayments, and 16,200 in insurance and fuel. Purchase-side money accounts for 66.6% of the total and running costs for 33.4%.

What Most People Overlook When Buying a Car

This calculator covers four things: the cash paid upfront, the loan repayments, insurance, and fuel. It covers nothing else. Servicing, tyres, brake pads, registration and annual vehicle taxes, parking, tolls, and repairs outside a warranty are all absent from the 48,525.65. So is resale value. The output is the total cash leaving the account over the term rather than the economic cost of the years driven, and those two figures pull in opposite directions: leaving out maintenance drags the number down, while charging the full purchase price with no credit for what the vehicle is still worth at the end pushes it up.

Understanding Depreciation as a Real Cost

Depreciation is the gap between what a vehicle cost and what it is worth later, and no invoice ever arrives for it, which is part of why it slips out of household budgets. In accounting it is a recognised expense rather than a bookkeeping nicety: under IAS 16 Property, Plant and Equipment, an asset's cost less its residual value is spread across its useful life as a depreciation charge. A car does the same thing sitting on a driveway, silently. This tool does not model that: it charges the full purchase price and credits no resale value, so the residual side is handled separately by the Car Depreciation Calculator.

Run it with sensible defaults

Purchase price 28,000, down payment 5,000, finance rate 7%, term 5 years, insurance 120 a month and fuel 150 a month produce 48,525.65 in total and 808.76 a month all-in. The loan itself is 23,000, the level monthly repayment 455.43, and the interest across all 60 payments 4,325.65. These are round starting numbers, not a benchmark for any particular market.

The levers in this calculation

Purchase price dominates. Raising it 10% lifts the five-year total by 6.86%, and a 1% change moves the total 0.69%. Fuel at +10% adds 1.86%; insurance at +10% adds 1.48%. The finance rate contributes 0.94% for the same relative change, though across its full 0-25% input range the swing is far wider: 44,200 at zero and 61,704.83 at 25%, a spread of 17,504.83. Down payment is the odd one out, because raising it 10% trims the total by only 0.19%. The money moves from the loan column to the upfront column rather than leaving the calculation, so only the interest it avoids shows up. Term length cuts both ways: one year totals 32,121.38 at 2,676.78 a month, seven years totals 56,839.06 at 676.66 a month.

How the math works

The loan is the purchase price minus the down payment. That balance is amortised at the finance rate over the term with the standard level-payment formula, so every instalment covers interest first and principal second. The total then adds three things: the down payment, all of the repayments, and twelve months of insurance and fuel for each year of the term. Fuel is entered as a flat monthly amount rather than derived from distance and price per litre, which keeps the input simple but also holds fuel spending constant for the whole term; IEA transport data tracks how much road fuel demand and prices actually move between markets and between years. Nothing else in the model varies over time, and no figure is discounted to present value.

When the result says "wait"

The figure that tends to prompt a second look is not the total but the all-in monthly number. At the defaults it is 808.76 against a headline repayment of 455.43, a gap of 353.33 a month that exists before a single service, tyre or registration renewal. Where that all-in figure sits relative to a monthly budget is a different question from whether the total looks large, and the calculator answers neither. It only makes the distance between the advertised payment and the running total visible.