APY Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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APY Calculator is most useful as a scenario tool: change one assumption at a time and watch how the modeled return, value, rate, or risk measure responds.

What this calculator does

APY Calculator calculates annual percentage yield and a deposit growth projection from APR, compounding frequency, initial deposit, and term. It uses only the information collected by this interface; costs, taxes, rates, market data, or operating assumptions that are not shown are not silently added to the result.

How to use it

Enter Currency, Initial deposit, Annual percentage rate of charge (APR), Compound frequency, and Term. Keep percentage assumptions in the units shown on the form and make sure the time unit of rates matches the term or period count. The currency selector changes display currency only; it does not perform an exchange-rate conversion. Before using the result in a decision, recheck unusually large or negative values against the source data rather than assuming the calculator is correcting an inconsistent input.

How the calculation works

APY = (1 + APR/m)^m − 1, where m is the number of compounding periods per year. The calculator also applies the same periodic compounding to the initial deposit over the entered term to estimate ending balance and interest earned.

Example

At 5% nominal APR compounded 12 times a year, APY is about 5.116%. A $10,000 deposit over 5 years grows to about $12,833.59 under that constant-rate assumption.

How to interpret the result

Interpret the result as a modeled finance quantity, not a forecast or recommendation. Returns, rates, correlations, cash flows, fees, taxes, and market prices can change, so the most useful practice is to test a range of plausible inputs rather than treating one scenario as certain.

Limitations and notes

The model assumes the inputs remain constant for the calculation. It does not automatically include taxes, inflation, transaction costs, liquidity constraints, changing rates, or sequence-of-returns risk unless those items appear as fields. Past or assumed returns are not guarantees of future results, and the output is not individualized investment advice.