Car Depreciation Calculator

Estimates how much a car will be worth each year from its purchase price and a depreciation rate you choose, and works out the yearly rate your own car has actually lost.

How to use

1. Enter the "Purchase price" and the "Age of the car when bought" (0 for a new car).
2. Choose a "Method": "Declining balance", "Straight line" or "Your own rate per year", and enter the rates. "Load example: 20% first year, then 15%" fills in an assumed example.
3. Set "Value after" to the point you want to know; the estimated value, value lost and depreciation per month and per km or mile appear at once.
4. Under "Find the real rate", enter what you paid, the value today and the years owned to get your car's average yearly rate, then press "Use this rate above".

How it works

• Declining balance: value at year end = value at year start × (1 − rate). The first-year rate applies only to a new car's first year.
• Straight line: (purchase price − end value) ÷ useful life each year. Average yearly rate = 1 − (value today ÷ purchase price)^(1 ÷ years).
• No default rates are given as fact and no used-car prices are looked up; the example rates are assumptions that vary widely by model and market.

Questions and answers

How much does a car lose in value per year?

It differs widely by model, age, mileage and market. Look up what similar used cars sell for and use "Find the real rate" to turn that into a yearly rate.

How do I calculate depreciation per km?

Divide the value lost by the distance driven. 12,660 lost over 3 years at 15,000 km a year is 12,660 ÷ 45,000 = 0.28 per km.

What is the difference between declining balance and straight line?

Declining balance takes a percentage of the remaining value, so the yearly loss shrinks over time. Straight line takes the same amount every year.

Can I enter a different rate for each year?

Yes. Choose "Your own rate per year" and type the rates for year 1, year 2 and so on, separated by commas; the last rate repeats.