Finance

Equivalent interest rate calculator

Convert a compound interest rate between month, quarter, half-year and year.

The fields start with an example. Replace it with your own numbers.

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Equivalent annual rate

12.6825%

1% per month is equivalent to 12.6825% per year with compound interest.

How this is calculated →
  • Quarterly3.0301%
  • Semiannual6.152%
  • Nominal annual rate (× 12, APR)12%

For compound interest. With simple interest the conversion is proportional (1% a month = 12% a year).

How to convert rates

With compound interest, a rate for one period becomes another by raising to a power: i₂ = (1 + i₁)^(n₂/n₁) − 1, with n in months. From 1% a month to a year: 1.01¹² − 1 = 12.6825%.

Going back uses the root: 12% a year is 1.12^(1/12) − 1 = 0.9489% a month. Multiplying the monthly rate by 12 gives the nominal rate (APR), which is lower than the effective rate (APY).

Frequently asked questions

What is 1% a month per year?

12.68% a year compounded (the APY). The 12% you get by multiplying by 12 is the nominal rate, or APR.

What is the difference between APR and APY?

APR is the nominal annual rate; APY is the effective annual rate including compounding. 12% APR compounded monthly is 12.68% APY.

Can I use it to compare loans and savings?

Yes. Convert every rate to the same basis (monthly or annual) before comparing.

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