Max Drawdown Calculator

The drawdown recovery problem

Losses and the gains needed to undo them are not symmetric. Lose 10 percent and you do not need 10 percent to get back; you need more, because you are now earning that return on a smaller base. The deeper the hole, the more dramatic the math becomes, which is why a large drawdown can be mathematically difficult to recover from even with a good strategy.

The recovery figure comes from a simple relationship: required gain = drawdown / (1 - drawdown). At a 50 percent loss you must double the remaining capital just to break even, and at 75 percent you need to quadruple it. This table is the single most useful reason to keep drawdowns shallow. Avoiding the deep hole is far easier than digging out of it.

Modeling a losing streak

Drawdowns are usually created by a run of consecutive losses, and losing streaks are far more common than intuition suggests. Even a strategy that wins 60 percent of the time will, over a few hundred trades, routinely produce stretches of five to ten losers in a row. Planning around the streaks that will happen, rather than the average outcome you hope for, is the whole point.

The calculator above uses a compounding model where each loss is taken on the reduced balance:

Final Balance = Start x (1 - loss%)^n

Worked example: start with $10,000, risk 2 percent per trade, and suffer 8 consecutive losses. The balance becomes 10,000 x (1 - 0.02)^8 = 10,000 x 0.8508 = $8,508. That is a drawdown of $1,492, or about 14.9 percent. Notice it is slightly less than 8 x 2 = 16 percent, because each successive loss is calculated on a smaller account. Now double the risk to 4 percent per trade over the same 8 losses and the balance drops to 10,000 x 0.96^8 = $7,214, a 27.9 percent drawdown that, per the table above, needs a 38.7 percent gain to recover.

What is an acceptable max drawdown?

There is no universal number, but there are well-worn ranges. Many discretionary retail traders operate with strategies that can dip 15 to 25 percent in a bad year. Professional and institutional managers tend to be far more conservative, frequently capping acceptable drawdown around 10 to 20 percent, and prop firms often enforce hard limits in the 5 to 10 percent region with automatic shutdown if they are breached.

The reason the pros stay shallow is partly the recovery math and partly psychology and business reality. A fund that draws down 30 percent watches its investors leave, and an individual who watches a third of their capital evaporate rarely keeps trading the plan with a clear head. A drawdown you can sit through calmly is worth more than a marginally higher return you cannot stomach.

How to reduce drawdown

Drawdown is something you engineer, not something you suffer. The biggest lever is how much you risk on each position. Cutting risk per trade from 2 percent to 1 percent roughly halves the depth of any given losing streak, at the cost of slower growth. Decide that trade-off deliberately rather than by accident.

• Size positions off a fixed fractional risk so every loss costs the same small slice of equity, and that slice shrinks automatically as the account does.
• Keep risk per trade modest. One to two percent is the common range; above that, normal losing streaks turn into account-ending drawdowns.
• Diversify across uncorrelated setups, instruments, or time frames so a single bad market regime cannot drag everything down at once.
• Use defined stops on every trade. An undefined worst case is the fastest route to an open-ended drawdown.
• Consider scaling risk down after a string of losses and back up as the equity curve recovers, rather than holding constant size through a slump.

Run a few scenarios through the calculator with your real win rate and risk per trade. If a plausible losing streak produces a drawdown you would not be comfortable holding through, lower the risk until the worst case is one you can live with.