Risk calculator: stake size and how many losses a balance survives

The risk calculator turns two inputs — your balance and the share of it you're willing to risk per trade — into a stake size, and shows how long that balance lasts through a losing streak. It's the least exciting calculator on the site and probably the most useful.

Stake size from risk percentage

Stake = balance × risk %

With a $500 balance:

On a fixed-payout trade, the stake is exactly what you can lose, so "risk per trade" and "stake" are the same thing. That makes position sizing simpler than in most markets: there is no stop-loss distance to calculate. Keep in mind the minimum stake of $1: with a $50 balance, 1% would be $0.50, which is below the minimum, so very small balances force a higher risk percentage than you might want.

How many losses in a row a balance survives

There are two ways to keep the stake constant.

Fixed amount. If you always stake the same dollar amount, the number of losses to zero is simply balance ÷ stake. $500 at $10 a trade survives 50 losses; at $50 a trade, 10.

Fixed percentage of the current balance. If you recalculate the stake from the balance after each trade, the balance after n losses is:

Balance after n losses = balance × (1 − risk %)ⁿ

After 10 losses in a row:

The percentage method never quite reaches zero, but it shrinks your stakes as the balance falls, which slows the damage.

Why a small percentage matters

Losing streaks are normal, even for a trader with a win rate above 50%. As an illustration: at a 55% win rate, the chance that any particular five trades are all losses is 0.45⁵, roughly 1.8%. Over a few hundred trades, a streak of six or more losses in a row is entirely ordinary. A 10% risk per trade turns that ordinary streak into a deep hole.

And holes are harder to climb out of than to fall into. A 20% drawdown needs a 25% gain to recover; a 50% drawdown needs 100%. See drawdown and recovery and risk per trade.

Putting it together

Choose a risk percentage you'd still be comfortable with after ten losses in a row — for many people that's 1–2%. Check the resulting stake against the minimum. Then use the profit calculator to see the break-even win rate for your payout. Risk control doesn't make trading profitable; it only keeps you in the game long enough to find out whether your approach works. You can lose the full amount of every trade, so trade only money you can afford to lose.