Compound Growth Calculator

Illustration only. This calculator applies a fixed percentage every period to show how compounding works. It is not a forecast, a projection or a promise of any return. Real trading results vary from period to period, losing periods are common, and you can lose money.

How to use it

Enter a starting balance and the percentage change per period. You can enter a negative number to see how losses compound.
Enter the number of periods and, if you like, an amount added each period.
The result shows the ending balance, the total paid in and the change from compounding.

How it works

Each period the balance is multiplied by one plus the rate, then any addition is made: new balance = balance × (1 + rate) + addition. With no additions this is the familiar formula start × (1 + rate) to the power of the number of periods.

Worked examples

Start	Change per period	Periods	Ending balance
1,000	1% rise	12	1,126.83
1,000	0%, adding 100 each period	12	2,200.00
1,000	1% fall	12	886.38

Why losses matter more

Compounding works in both directions, and losses need larger gains to recover. After a 10% loss you need about 11.1% to get back to the start; after a 25% loss you need 33.3%; after a 50% loss you need 100%. This is one reason traders keep risk per trade small. See risk management for traders and the lot size calculator.

Frequently asked questions

Is this a projection of trading returns?

No. It applies the same percentage every period purely to show the arithmetic of compounding. Real results are uneven, often negative, and cannot be predicted.

What does a negative rate show?

It shows how a balance shrinks when losses repeat. For example, 1,000 falling 1% per period for 12 periods ends at about 886.38.

Why does a 50% loss need a 100% gain to recover?

After a 50% loss, 1,000 becomes 500. Getting back to 1,000 means doubling 500, which is a 100% gain.