HHelpje

Compound Interest Calculator

Calculate how your capital grows with interest and regular contributions over time.

Final value
£265,277.59
Interest earned
£135,277.59
Total contributions
£130,000.00
Capital multiplier
×2.04

Results are indicative — they do not account for capital gains tax, inflation, or management fees.

Capital growth year by year

YearDepositedInterestValue
1£16,000.00£815.40£16,815.40
2£22,000.00£2,051.16£24,051.16
3£28,000.00£3,733.20£31,733.20
4£34,000.00£5,889.05£39,889.05
5£40,000.00£8,547.94£48,547.94
6£46,000.00£11,740.89£57,740.89
7£52,000.00£15,500.84£67,500.84
8£58,000.00£19,862.77£77,862.77
9£64,000.00£24,863.79£88,863.79
10£70,000.00£30,543.34£100,543.34

Compound interest calculator — how it works and what it calculates

Our free compound interest calculator lets you check how much your capital will grow at a given interest rate with regular contributions. Enter the starting amount, annual interest rate, investment period, and compounding frequency — results appear instantly. You can also set monthly or annual top-ups, which mirrors systematic saving in a deposit account, fund, or pension scheme. The calculator computes the final value, total contributions, and interest earned.

Annual table — track your savings growth year by year

Below the results you will find a detailed annual table showing how the portfolio value changes over the years. You can see cumulative contributions, cumulative interest, and total value at the end of each year. For long time horizons you can expand the full table with a button. It is a great way to see the compound interest effect in action — year after year the interest increment accelerates.

Frequently asked questions

What is compound interest?
Compound interest is a mechanism in which interest is added to the principal and then starts generating further interest. As a result, capital grows exponentially — the longer you invest, the faster your funds accumulate.
How often should interest be compounded?
The more frequent the compounding, the higher the effective return. Daily compounding yields slightly more than monthly, which in turn yields more than quarterly or annual. However, the differences are usually small at the same nominal interest rate.
What are regular contributions and how do they affect the result?
Regular contributions are funds added to the principal every month or every year. Each contribution starts working from the moment it is made and is itself subject to compound interest. Systematically saving even small amounts can dramatically increase the final value of your savings.
Is the calculator free and private?
Yes, the calculator is completely free and runs exclusively in your browser. No entered data is sent to any server or stored anywhere.

See also