Compound Interest Calculator
💷 Money & growth. Use the Compound interest (compounded k times a year) formula to find final amount, amount invested p, rate, times per year k, years: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Final amount | £ |
| Amount invested P | £ |
| Rate | % per year |
| Times per year k | no unit |
| Years | no unit |
Worked example
Find the final amount when Amount invested P = 1000 £, Rate = 5 % per year, Times per year k = 12, Years = 3.
Using A = P(1 + r/100k)^(kt): Final amount = 1161.5 £.
Frequently asked questions
What is the formula for Compound interest (compounded k times a year)?
A = P(1 + r/100k)^(kt).
What do the letters stand for, and what units are used?
Final amount in £, Amount invested P in £, Rate in % per year, Times per year k, Years.
How do you calculate final amount?
Put the values into A = P(1 + r/100k)^(kt). For example, with Amount invested P = 1000 £, Rate = 5 % per year, Times per year k = 12, Years = 3, final amount = 1161.5 £.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (final amount, amount invested p, rate, times per year k, years) and fill in the others: it rearranges the formula for you.
