Finance calculator (time value of money)
Solve for the future value, starting amount, regular deposit, interest rate or time in any savings or investment problem.
About the finance calculator (time value of money)
Solve for the future value, starting amount, regular deposit, interest rate or time in any savings or investment problem.
Part of SmartCalcy’s investing & savings tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the finance calculator (time value of money)
What it calculates and when to use it
A time-value-of-money solver. Fill in what you know and choose the one thing to find: the future value, the starting amount, the regular deposit, the interest rate or the time needed.
How to use it, step by step
- Choose what to work out.
- Fill in the remaining boxes: start amount, regular deposit, target, rate and years.
- Pick the deposit and compounding frequency. Tick the box if deposits are made at the start of each period.
- Read the answer and, for future value, the year-by-year table.
What each input means
- Starting amount – What you have now.
- Regular deposit – Added every period.
- Target amount – The balance you want.
- Interest rate – The nominal yearly rate. It compounds once per deposit period.
- Deposits at the start – Annuity-due timing. Each deposit earns a period of interest more.
How to read the results
- Future value – The balance at the end.
- Total put in and interest earned – Your deposits and the growth.
The formula
FV = PV × (1 + i)^n + PMT × ((1 + i)^n − 1) ÷ i, where i is the rate per period (yearly rate ÷ periods a year) and n the number of periods. For deposits at the start, multiply the deposit term by (1 + i). The other four unknowns are solved from this equation; rate and time use the exact equation or a numerical search.
A worked example
5,000 invested with 200 a month at 5% a year for 10 years, compounded monthly, grows to 39,291.50. You pay in 29,000 and earn 10,291.50 of interest.
Assumptions and limits
- The rate is fixed and compounding matches the deposit frequency.
- No tax, fees or inflation.
Common mistakes
- Entering a monthly rate in the yearly rate box.
- Mixing deposit periods and compounding periods.
Frequently asked questions
What if the rate is zero?
Growth is just your deposits added to the start amount.
Can the answer be impossible?
Yes. For example a target below what your deposits already reach, or a rate that would need to be below −99%. The calculator says so.
Related tools
Details
- Total you put in
- £29,000.00
- Interest earned
- £10,291.50
Year by year
| Year | Deposits | Interest | Balance |
|---|---|---|---|
| 1 | £2,400 | £312 | £7,712 |
| 2 | £4,800 | £762 | £10,562 |
| 3 | £7,200 | £1,358 | £13,558 |
| 4 | £9,600 | £2,107 | £16,707 |
| 5 | £12,000 | £3,018 | £20,018 |
| 6 | £14,400 | £4,098 | £23,498 |
| 7 | £16,800 | £5,356 | £27,156 |
| 8 | £19,200 | £6,801 | £31,001 |
| 9 | £21,600 | £8,443 | £35,043 |
| 10 | £24,000 | £10,292 | £39,292 |