Convert a nominal APR to APY, or APY back to APR, with annual, semiannual, quarterly, monthly, daily, or continuous compounding.
Nominal APR and effective APY
APR here is the nominal annual rate divided across compounding periods. APY is the effective annual yield after that compounding. More frequent compounding raises APY when the nominal rate is positive. This is a compounding conversion, not a loan APR that folds in origination fees.
A 5% APR compounded monthly is an APY of about 5.11619%. $10,000 left for one year at that APY earns about $511.62. Converting 5.11619% APY back with monthly compounding returns the 5% APR. Continuous compounding on 5% APR is about 5.12711% APY.
What this conversion leaves out
Account fees, teaser rates, tax, and a rate that changes during the year sit outside the formula. A loan APR with fees deducted at disbursement is a different cash-flow rate; use the loan APR calculator for that.
Frequently asked questions
Is APY always higher than APR?
When the nominal rate is positive and compounding is more than once a year, yes. At 0% they match. Continuous compounding is the upper limit for a given positive APR.