Finance Calculator (TVM)
The five time-value-of-money keys of a financial calculator in your browser. Find a payment, rate, term, present value or future value.
🔒 Runs entirely in your browser. Nothing you enter is sent to a server.
Every loan, savings plan, annuity and investment comes down to five numbers: how many periods (N), the interest rate (I/Y), the value today (PV), the payment each period (PMT) and the value at the end (FV). Know any four and you can find the fifth. That is exactly what the time-value-of-money keys on a BA II Plus, HP 12C or TI-84 do. This finance calculator gives you the same thing online, free.
How to use the finance calculator
- Choose what to solve for. The box for that value is hidden, like pressing CPT on a financial calculator.
- Enter the other values. Use the sign convention: money you receive is positive, and money you pay out is negative.
- Set P/Y, the periods per year, and whether payments are at the end or start of each period.
The result shows the value, what it means, and the total of all payments.
The time value of money equation
All five keys are linked by one equation, where i is the rate per period (I/Y ÷ P/Y) and n is N:
PV × (1 + i)^n + PMT × (1 + i × type) × ((1 + i)^n − 1) ÷ i + FV = 0type is 0 for payments at the end of each period and 1 for the start. The calculator rearranges this directly for PV, PMT, FV and N, and solves it numerically for I/Y.
Worked example: a mortgage payment
A $300,000 mortgage at 6.5% for 30 years, paid monthly:
- N = 360, I/Y = 6.5, PV = 300,000 (you receive it), FV = 0, P/Y = 12, END.
- Solve for PMT: −$1,896.20. The minus sign shows it is money you pay.
- Total of all payments: −$682,633.47, so the interest is $382,633.47.
More problems the same keys solve:
| Problem | Enter | Solve | Answer |
|---|---|---|---|
| Save $200 a month at 7% for 30 years | N 360, I/Y 7, PV 0, PMT −200 | FV | $243,994.20 |
| Car loan of $25,000 at $495 a month for 60 months | N 60, PV 25,000, PMT −495, FV 0 | I/Y | 6.9975% |
| How long to repay $15,000 at 9% paying $400 | I/Y 9, PV 15,000, PMT −400, FV 0 | N | 44.2 months |
| Lump sum needed for $1,500 a month for 20 years at 5% | N 240, I/Y 5, PMT 1,500, FV 0 | PV | −$227,287.97 |
Tips
- Write down the cash flows before you start. Decide which are in and which are out, and give them signs.
- Match N to P/Y. Monthly payments for 30 years means N = 360 with P/Y = 12.
- Use BGN for leases, rent and annuities due. Payments made in advance are worth slightly more.
- For a full payment schedule, the amortization calculator shows how each payment splits between interest and principal.
Common mistakes
- Entering every value as positive. With no money going out, there is no solution.
- Leaving P/Y at 12 for yearly problems. Set it to 1 if periods are years.
- Typing the rate as a decimal. Enter 6.5 for 6.5%, not 0.065.
- Forgetting that FV includes PV growth. If you start with a balance, enter it as PV, or the future value will be too low.
Frequently asked questions
Why is the payment shown as a negative number?
Financial calculators use a sign convention, where money you receive is positive and money you pay out is negative. If you borrow $300,000 (PV positive), the payments you make are negative. Enter values with the same convention, or the calculator can't find an answer.
What do P/Y and BGN mean?
P/Y is the number of periods per year, 12 for monthly payments. BGN means payments happen at the start of each period, as with rent or a lease, and END means at the end, as with most loans. Set them to match your problem before solving.
Is I/Y the yearly rate or the monthly rate?
Enter the yearly rate, like on a BA II Plus. The calculator divides it by P/Y to get the rate per period. When you solve for I/Y it shows both the yearly rate and the rate per period.
Why do I get "no answer"?
Usually the signs are wrong. At least one of PV, PMT and FV must be money in (positive) and one must be money out (negative). A rate of zero with nothing to repay, or N of zero, also has no solution.