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Prime Rate Calculator

Compute effective lending rate and payments when interest is prime plus spread.

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About this calculator

Prime rate and loan pricing

The prime rate is a benchmark rate banks charge their most creditworthy corporate customers. Many consumer products are priced as prime plus a spread (margin), such as prime + 2%.

When the prime rate rises, variable loan payments typically increase. This calculator shows payment and total interest at your assumed prime and spread.

Effective rate = Prime rate + Spread

Reference tables & standards

Federal Reserve H.15 — prime rate context

Source: U.S. Federal Reserve (H.15 selected interest rates)
TermMeaning
Prime rateReference rate posted by major banks
Spread / marginAdditional percentage added for a specific loan
Variable loanPayment changes when prime or index changes
Fed funds rateInfluences but is not identical to prime

Calculations are for educational and planning purposes only. They are not financial, tax, or investment advice. Rates, fees, and inflation assumptions vary in real markets.