PlanetToolbox
Interest Rate Calculator
Solve an implied interest rate from a loan payment, simple interest amount, or compound return target.
Annual rate
5%
Effective annual
5.12%
Total interest
$1,323
Rate inputs
Solve an implied interest rate
Rate result
- Nominal annual rate
- 5%
- Effective annual rate
- 5.12%
- Total interest
- $1,323
- Total paid or future value
- $11,323
Formula
Methodloan payment APR solved iteratively from the amortization formula
Interest rate assumptions
The loan-payment mode solves the rate implied by the amount, payment, and term you enter. It does not fetch live lender rates or include fees unless those fees are already reflected in the payment.