APY shows the true annual return including the effect of compounding.
What this calculator does
APY = (1 + r/n)^n − 1. The more frequent the compounding, the higher the APY.
When to use this calculator
Reach for this tool whenever a financial decision hinges on this type of calculation. Small differences in rate or term become large differences in total cost or return over multi-year horizons — differences that only become visible when you run the actual numbers.
Common mistakes
A frequent error is using annual rates where monthly rates are required (or vice versa). Simply dividing an annual rate by 12 is only an approximation — the correct conversion for compound calculations uses the (1 + r)^(1/12) − 1 formula.
Real-world scenarios
An employee receives a counter-offer from another employer: a £4,000 salary increase but no pension contribution versus the current role's lower salary with 8% employer pension. Running both through the finance calculator shows the true net financial value of each offer.
Frequently asked questions
What is the difference between APR and APY?
APR is the nominal rate. APY is the effective return including compounding.