Why future value matters
A car payment is a fixed monthly outflow for years. Compounding the same amount shows the opportunity cost of that commitment.
It is not an argument against owning a car, but it makes the trade-off visible.
Worked example
£400 a month for 4 years at a 5% return grows to £21,205.95. You pay in £19,200, so the growth is £2,005.95.
A higher return or a longer period increases the gap between what you pay in and what you end up with.
Using the figure
Compare it with the interest you pay on the loan. If the loan costs more than the investment returns, overpaying is the better use of spare cash.
Investment returns are not guaranteed; use a cautious rate for planning.
Inputs for the car loan future value calculator
Amount each month
The monthly amount, such as your car payment.
Yearly return
The yearly rate the money could earn.
Years
How long the payments continue.
CALCULATOR QUESTIONS
Car loan future value calculator questions
What does £400 a month become in 4 years?
£21,205.95 at a 5% return, including £2,005.95 of growth.
Is the return guaranteed?
No. Use a rate you can defend, and consider a range of outcomes.
Does inflation matter?
Yes. In real terms the figure is lower; subtract expected inflation for a today's-money view.
Should I invest instead of buying a car?
That depends on need. The comparison is useful, not decisive.