Profit calculator: payout, expected value and break-even win rate

The calculator above answers three questions: how much a single trade pays if it wins, what a series of trades is worth on average at a given win rate, and what win rate you need just to break even. The formulas are simple, and knowing them is more useful than any single result.

One trade: win, loss or tie

For a trade with stake S and payout percentage P (shown before you open the trade and fixed once it's open):

• Win: profit = S × P. You get back S + S × P.
• Loss: result = −S. You lose the stake, never more.
• Tie (the price at expiry equals the entry price): result = 0, the stake is refunded.

Example: a $20 stake at 85% payout. A win adds $17, a loss costs $20, a tie returns the $20.

Notice the asymmetry. The win is always smaller than the loss, because payouts on Sky Trade are between 20% and 94% — always below 100%.

Expected value at a given win rate

If you win a share W of trades (ignoring ties, which are worth 0), the average result per trade is:

EV = W × S × P − (1 − W) × S

Example with a $10 stake and 85% payout:

• At a 55% win rate: 0.55 × 8.50 − 0.45 × 10 = 4.675 − 4.50 = +$0.175 per trade.
• At a 52% win rate: 0.52 × 8.50 − 0.48 × 10 = 4.42 − 4.80 = −$0.38 per trade.
• At 50% (a coin flip): 0.50 × 8.50 − 0.50 × 10 = −$0.75 per trade.

These are averages over many trades, not forecasts. Any real sequence will swing around them, sometimes a lot. And the win rate is the hard part: entering 55% into the calculator is easy, achieving it is not.

Break-even win rate

Set EV to zero and solve for W:

Break-even W = 1 / (1 + P)

Below the break-even rate, you lose money on average regardless of stake size. This is why random trading — a 50% win rate — loses over time at any payout below 100%. See the break-even win rate and expected value entries for more.

Using the result sensibly

A positive EV in the calculator only says "if this win rate were real and stable, this is the average". Win rates measured over a few dozen trades are mostly noise. Log a large sample first — on the demo account if you like — and keep stakes small relative to your balance; the risk calculator helps with that.