Forex Compounding Calculator

What compounding means for a trader

Compounding is what happens when this month's profit becomes part of next month's position size. Withdraw your gains and your growth is a straight line: the same account, earning the same amount, over and over. Reinvest them and the line bends upward, because every gain enlarges the base the next gain is computed on. The difference looks small at first and then it is not: $10,000 earning 5% a month pays $500 every month if you take the profit out, but left to compound it ends the year at $17,958.56 - $1,958.56 more than the $16,000 the take-the-profit version produces, from identical trading.

The same force works against you. Losses shrink the base too, and a drawdown compounds in reverse: lose 20% and you need 25% just to get back to flat. That asymmetry is why this page refuses to be a fantasy machine. The calculator shows the curve your inputs imply, tells you what those inputs mean at a yearly scale, and - if you feed it your real stats - shows what losing streaks do to the textbook number. A compound calculator is only useful when the rate going in survives contact with reality.

The formula

Flat-rate compounding is one line of math:

The per-trade version replaces the guessed rate with your actual trading profile. If you risk a fraction k of the account per trade, win w of the time, and your average winner pays R times your risk, your expected growth per trade is:

The second line is the one almost nobody shows you. The first is an average; the second is what that average actually compounds to when wins and losses arrive in streaks, the way they do in real trading. It is always slightly lower, and the gap widens as you risk more per trade. The "from your stats" mode above plots both curves so the cost of variance is a number you can see, not a footnote.

A worked example

Say you trade a $10,000 account, and your last two quarters averaged out to 2% a month after costs - a strong, honest number. Compounded for 24 months with nothing added and nothing withdrawn, the schedule ends at $16,084: a 60.8% total return, with the balance crossing its first double at month 36 if you kept going. Add a $250 monthly deposit and the curve steepens meaningfully - deposits do more work in an account's early life than the growth rate does, which is the most underrated fact in account building.

Now type 10% into the same box. The 12-month projection triples the account, and one more year of make-believe puts it near 10x. The calculator will not stop you - it will just quietly note what that pace means per year, and you can decide which of the two spreadsheets you would rather show your future self.

Compounding vs fixed lot size

Fixed sizing keeps your risk constant in money terms: the account grows linearly and a bad month always costs the same number of dollars. Compounding scales the position with the balance: growth turns geometric, but so do the drawdowns, because a 5% loss on a grown account is more money than a 5% loss on the starting one. Neither is wrong. Fixed sizing suits traders proving out a strategy; compounding suits a proven edge that deserves to scale. A common middle path is partial compounding - reinvest most of the profit, withdraw the rest on a schedule. The withdrawals field above models exactly that, and shows the month a too-aggressive draw would bleed the account dry.

What growth rate is actually realistic?

The honest anchor points, so the number you type has some adult supervision. The best-performing fund in recorded history - a quant fund closed to outside money since the early nineties - compounded roughly 39% a year, net, over three decades. The most famous investor alive averaged just under 20% a year over sixty years, and that was enough to make him one of the richest people on earth. A trader sustaining "10% a month" would be compounding at 214% a year - five times the greatest fund ever, from a home office.

Meanwhile the base rates run the other way. European regulators force brokers to publish the share of retail accounts that lose money; across major brokers it sits between 74% and 89%. The largest academic study of day traders who persisted for 300+ sessions found 97% of them lost money over the period studied. And the most popular prop-firm evaluations - the industry's own bar for "good enough to fund" - ask traders to make 10% once, with no time limit, without losing 10% along the way. That is the professional standard: ten percent, one time, risk controlled. Not ten percent a month.

So the honest range for a consistent retail trader is roughly 1 to 3% a month. Compounded, that is 13 to 43% a year - hedge-fund territory, from numbers that sound almost boring typed into a calculator. That is the entire trick of compounding: the inputs are modest, the horizon does the work. The preset chips above are labeled the way they are on purpose.

Using the schedule, goals, and exports

Pick the period that matches how you actually trade - per trade, day, week, or month - and the schedule prints every step: starting balance, the gain, any deposit or withdrawal, and the ending balance that becomes the next row's start. Milestones are marked where the balance first doubles and where it crosses round numbers. The goal field solves the question people actually search for - "how long until $100k?" - in both directions: periods needed at your rate, and the rate needed in your timeframe. The link button shares your exact plan, and the CSV download gives you the schedule as a spreadsheet, cents included, if you would rather keep the plan where your other trading records live.

Two sibling tools feed this one. The Position Size Calculator turns a risk percentage into an exact lot size, which is how "risk 1% per trade" stays true as the balance compounds. The Risk/Reward Calculator pressure-tests the win rate and ratio you feed the "from your stats" mode - the same expectancy math connects all three.

Frequently asked questions