Compound Growth Calculator for Traders

Updated 31 October 2026 · Written by Broker Atlas Guides Desk · Data checked by Broker Atlas Data Desk

Short answer

Each month the balance is multiplied by (1 + monthly return) and the monthly deposit is added: balance = balance × (1 + r) + deposit, repeated for each month. $1,000 at 3% a month for 12 months grows to about $1,426. The result assumes the same return every month, which no trading strategy delivers. Use it to see what a return target implies, not to forecast.

How to use it

Starting balance: what you begin with. Any currency works; the result is in the same currency.
Monthly return (%): the average return you want to test. Negative values work too.
Months: how long to compound (up to 600).
Monthly deposit: added at the end of each month. Enter a negative figure to model regular withdrawals.

The formula

For each month: balance = balance × (1 + monthly return) + monthly deposit

Without deposits that’s simply start × (1 + r)^months.

Worked examples

Example 1: no deposits. $1,000, 3% a month, 12 months. 1,000 × 1.03^12 = 1,425.76, shown as 1,426, a gain of 426.

Example 2: with deposits. $2,000, 2% a month, 24 months, plus $100 a month. The starting balance grows to 2,000 × 1.02^24 ≈ 3,216.9; the deposits grow to 100 × (1.02^24 − 1) ÷ 0.02 ≈ 3,042.2. Total 6,259, of which 2,000 + 24 × 100 = 4,400 is your own money and 1,859 is gain.

What the result means

The calculator shows the arithmetic of compounding: growth accelerates because each month’s return is earned on a larger balance. It also shows how sensitive the outcome is to the return you assume. Try the same $1,000 for 12 months:

Monthly return	Final balance	Annual equivalent
1%	1,127	12.7%
3%	1,426	42.6%
5%	1,796	79.6%

What it takes to double

Working backwards is often more revealing. To double a balance with no deposits you need a monthly return of 2^(1/months) − 1:

Doubling in	Monthly return needed
6 months	12.2%
12 months	5.9%
24 months	2.9%
60 months	1.2%

Enter any of these rates with the matching months and the calculator shows roughly twice your starting balance. If a plan needs one of the top rows, the position sizes it implies are usually far above the 1–2% risk per trade used in the position size examples.

Why real results look different

Returns vary. A month of −10% followed by +10% leaves you at 99% of where you started, not 100%. Losing months cost more than winning months of the same size give back.
Drawdowns limit size. Most traders reduce position size after losses, which slows the recovery. The position size calculator shows how the percent-risk method scales size with the balance.
Costs and tax. Spreads, commission and swap reduce every month’s return, and profits may be taxable where you live. General pointers, with links to official sources, are in forex trading tax.
Leverage cuts both ways. Pushing for a higher monthly return usually means larger positions. See risk management with high leverage.

A broker, signal seller or copy-trading provider who promises a fixed monthly return is a warning sign: read how to spot a scam broker and how copy trading works. If you’re starting small, starting forex with $100 covers realistic lot sizes.

Frequently asked questions

Is the deposit added before or after the month's return?

After. Each month the balance earns the return first and then the deposit is added, so a deposit starts earning the following month.

What does the figure under the result mean?

The total gain from returns: final balance minus the starting balance minus all monthly deposits.

Is 3% a month realistic?

Compounded, 3% a month is about 42.6% a year. Treat any steady monthly return, and anyone promising one, with scepticism: trading returns vary and include losing months.

Does it include withdrawals, tax or fees?

No. Enter a lower return to allow for costs, or a negative monthly deposit for regular withdrawals.