Finance

Car Effective Annual Rate Calculator (5 Years)

Convert a nominal annual rate to an effective annual rate. This car version uses a 5-year planning term as its starting point.

This result shows the true yearly rate after compounding, so it is the rate to compare with other car finance offers rather than the headline nominal rate alone.

Formula

Effective rate equals one plus nominal rate divided by periods, to the power of periods, minus one.

How it works

More frequent compounding raises the effective rate slightly above the nominal rate.

Worked example

Nominal rate 6%, compounding 12 times a year, term 5 years. Using the formula shown on this page, the effective annual rate is one plus 6 divided by 100 and then by 12, which is 1.005, raised to the power of 12, which is about 1.061678, minus one, which is 6.17%. That 6.17% is the same on every page in this group, because the term in years is a planning horizon, not an input in the formula. As a term illustration only, not a separate output of this page, every $10,000 borrowed for a car grows to about $13,488.50 over 5 years at the 6.17% effective rate, compared with about $13,382.26 at a flat 6% with no compounding. The difference, $106.25, is the cost of monthly compounding alone over 5 years, and the totals are rounded to the nearest cent.

Who this term suits for a car: a first-time car buyer checking a short car-loan quote, for example a used hatchback bought on a 5-year loan, where the buyer wants the true yearly cost before signing, not just the headline rate in the dealer's advert.

FAQs

What is an effective rate?
The effective rate is the true yearly rate after allowing for compounding during the year.

Is this car calculator exact?
No, it is an estimate for planning only, based on the numbers you enter.

Are these figures financial advice?
No, they are estimates for planning only, not financial advice. Check with a qualified adviser for decisions involving large sums.

How can a car buyer check the 6.17% figure by hand?
Take one plus 6 divided by 100 and then by 12, which is 1.005, raise it to the power of 12, which is about 1.061678, and subtract one. The result is 6.17%. If your dealer quote gives a different compounding frequency, use that number of periods instead of 12 and the answer will change.

Why does monthly compounding add only $16.78 on $10,000 in the first year?
Because the gap between 6.17% and 6.00% is only 0.17 points, and 0.17% of $10,000 is about $17. In the first year the gap is small, which is why a low headline rate can look harmless on a short car loan even though the true rate is higher.

Should a 5-year car loan be compared on the effective rate or on the headline rate?
On the effective rate. Two 5-year car loans can share a 6% headline rate yet cost different amounts if one compounds monthly and the other yearly, so comparing effective rates is the only fair way to choose between them.

Estimates only, not financial advice. Figures are approximate and do not include all fees, taxes, or changing rates unless stated.