SmartCarCosts

The calculator

This is where the spreadsheets live. Pick a car, tell us how long you'll keep it, and we'll rank cash, PCP, HP and leasing by what they truly cost, with the reasoning laid out. New to the idea? Read how it works first.

Compare the true cost

Can't find your make or model? Tell us in a thirty second survey and we'll use those requests to decide which cars to add next.

Assumptions (editable; defaults are typical UK figures)
OptionTrue costPer monthPer mile

True cost = everything you pay minus what you get back when you sell, in today's money (future amounts discounted at your investment rate). Lower is better.

View the data behind this curve
Model yearMedian asking priceListings sampled

The maths, honestly

Every way of paying for a car reduces to the same thing: a series of cash flows. Money out (price, deposit, payments, balloon), money back (what you sell it for). Comparing options by monthly payment ignores most of those flows. A £299 a month lease and a £299 a month PCP are wildly different products. So instead we compute, for the same car over the same period:

true cost = everything paid − resale value, all converted to today's money

"Today's money" matters. £10,000 you get back in four years is worth less than £10,000 now, because you could have invested it in the meantime. Economists call that the opportunity cost of capital. It's why paying cash isn't automatically the winner, and it's the assumption worth playing with most.

Where the depreciation number comes from

Each model's value curve is fitted from thousands of live UK asking prices: the same car observed at every age from one to nine years old. A three year old example tells you, roughly, what today's one year old will be worth in two years. We checked our curves against the residual forecasts manufacturers publish inside their own PCP offers, and they sit where retail prices should sit relative to trade floors. Reassuring, though we'd still call them estimates.

How each option is modelled

Before trusting any number here, read the honest caveats on the Why data? page. These are hand-crunched estimates meant to guide a decision, not absolutes.