What is an annual percentage yield calculator?

It converts a quoted nominal annual rate (APR) into APY by accounting for how often interest compounds in a year. The effective yearly rate after compounding is what that label describes.

What is the difference between APY and APR?

APR is often quoted as the simple nominal rate per year. APY is the effective annual rate after compounding, so APY is usually a little higher than APR when compounding happens more than once per year.

Why does an APY yield calculator ask for compounding frequency?

Interest can be credited yearly, monthly, daily, or on a continuous model. More frequent compounding means interest earns interest more often within the same year, which raises APY compared to annual compounding at the same APR.

APY Calculator | Annual Percentage Yield

Why use an APY yield calculator

Compare offers fairly

Two accounts can quote the same APR but pay different APY if compounding differs. Running the numbers here first lines up what growth really looks like over a year before you chase a headline rate.

Savings and deposits

Helpful when reading savings, money market, or CD style rates where the fine print mentions how often interest is credited. An annual percentage yield calculator view next to APR keeps comparisons honest.

Know what the math assumes

The APY calculator on this page uses standard textbook formulas. Your institution may round, use a different day count, or layer fees that change what you actually receive.

Formulas this page uses

This APY calculator implements the usual discrete and continuous APY definitions. Under the hood, r is the nominal annual rate in decimal form (APR% divided by 100). With n compounding periods per year, APY in decimal form is (1 + r/n)ⁿ − 1. The tool shows APY as a percent by multiplying that result by 100.

For continuous compounding, APY in decimal form is e^r − 1, then shown as a percent the same way.

With principal P and term t in years, the projected balance uses A = P(1 + r/n)^nt when there are n periods per year, and A = Pe^rt for continuous compounding. Interest earned is A − P.

Daily compounding here uses n = 365. Some products use 360 or business day counts. Always read the product terms when the number matters for a real decision.

How APY fits next to APR

In this APY calculator, APR often describes the nominal interest rate for a year before you fold in how often interest is credited. APY answers a different question: if you leave everything to compound under a stated schedule, how much do you effectively earn or owe over one full year?

Why frequency matters

When interest is credited more than once per year, each credit can earn further interest before year end. That is why compounding frequency matters and belongs in the inputs. More frequent compounding pushes APY above APR when the nominal rate stays the same.

When APY matches APR

If interest compounds once per year, there is no within-year compounding step, so APY and APR line up for the standard model used here.

For learning and planning only. Not tax, legal, or investment advice, and it does not replace your bank or advisor.