Financial / TVM 5-Key Calculator
Time-value-of-money solver. Provide four of {PV, FV, PMT, N, I/Y} — solve for the fifth.
Inputs
How it works
Uses the general TVM equation FV = PV·(1+i)^N + PMT·((1+i)^N−1)/i · due, where i = I/freq and due handles begin-of-period timing. Solves algebraically for FV/PV/PMT and numerically (bisection) for N and I/Y.
Frequently asked questions
What is the TVM 5-key?
The five variables every financial calculator (HP-12C, TI BA II Plus, etc.) uses: PV, FV, PMT, N, and I/Y. Know any four, solve for the fifth.
What's the sign convention?
Textbook convention treats outflows as negative and inflows as positive. This calc uses same-sign inputs for simplicity — interpret the direction based on your scenario.
When would I use this?
Loan payoff (solve PMT), retirement savings target (solve N or PMT), rate implied by an investment (solve I/Y), etc.
Ordinary vs annuity due?
Ordinary = payments at end of period (loans, most savings). Annuity due = payments at start (leases, annuities-in-advance).
Why does N sometimes not converge?
If PV/FV/PMT signs are inconsistent (e.g. you can never reach the target), the solver may fail. Check your inputs are internally consistent.
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View all investment →Results are estimates for educational purposes only and are not financial advice. Verify with a qualified professional before making decisions.
Last updated January 1970