Pick which variable to solve for — N, I/Y, PV, PMT, or FV — then fill in the remaining four. This uses the standard ordinary-annuity TVM equation behind every financial calculator's TVM keys.
The Time Value of Money (TVM) is the principle that a dollar today is worth more than a dollar in the future, because today's dollar can be invested and earn a return in the meantime. Every loan payment, investment projection, and savings-goal calculation on this site rests on this same idea — this tool exposes the underlying equation directly so you can solve for any one of its five variables instead of just one fixed output.
PV is present value — a lump sum you have today. FV is future value — what that lump sum (plus any payments) grows to. PMT is a recurring payment or contribution made each period. N is the number of periods. I/Y is the interest rate earned per period, entered as a percentage. Together, these five describe any stream made up of a starting lump sum plus equal periodic contributions growing at a fixed rate per period.
Solve for FV to project how a lump sum plus regular contributions will grow by a target date. Solve for PV to find what a future goal is worth in today's dollars. Solve for PMT to find the contribution needed each period to hit a target. Solve for N to find how many periods it takes to reach a goal. Solve for I/Y to back out what rate of return a known investment history actually implies.
This is a general-purpose TVM solver that computes any one of the five variables from the other four, the same way the TVM keys on a financial calculator work. For a purpose-built tool focused on lump-sum growth over time, see the Compound Interest Calculator; for a friendlier layout built specifically around regular contributions, see the Investment Calculator.
Worked example — solving for FV: N = 10 periods, I/Y = 6% per period, PV = $1,000, PMT = $100 per period. FV = 1,000 × (1.06)10 + 100 × ((1.06)10 − 1) ÷ 0.06 = 1,790.85 + 1,318.08 = $3,108.93. Feeding that same $3,108.93 back in as FV and solving for I/Y instead returns 6.00%, confirming the equation is being solved consistently in both directions.