TVM Calculator (Time Value of Money)
Solve for any one of N, I/Y, PV, PMT, or FV, just like the TVM keys on a financial calculator. Fill in four values and tap Solve on the one you want.
How it works
Why are some numbers negative?
TVM calculators use a cash-flow sign convention: money you receive is positive and money you pay out is negative. A loan is +PV (you receive the cash) with −PMT (you pay it back). Savings are −PV and −PMT (you pay in) with +FV (you get it back later). If you get an error, check your signs.
What do N and P/Y mean?
N is the total number of payments, not years. A 30-year mortgage with monthly payments has N = 360 and P/Y = 12. I/Y is always the annual rate; the calculator divides it by P/Y.
When should I use BEGIN mode?
When payments happen at the start of each period, like rent, leases, or saving at the start of each month. Loans and most savings plans use END.
How is I/Y solved?
There's no direct formula for the interest rate, so the calculator searches for the rate that makes all the cash flows balance, the same way a financial calculator does. It's accurate to many decimal places.
Prefer step-by-step entry? Try the RPN calculator, a favorite of finance pros, or the loan calculator for a full amortization table.