Bankroll Projection Calculator

A win rate and a unit size imply an outcome, and the gap between what people expect from theirs and what the arithmetic actually produces is usually large in both directions.

This projects a bankroll forward across a season, flat or compounding, and shows the range around the average — because the average is the one result you are least likely to get.

What The Projection Is Doing

The centre line is simple arithmetic. Your edge per dollar staked is (p × profit per dollar) − (1 − p), and total profit is that edge multiplied by the number of bets and the stake.

Worked example. A $2,000 bankroll, 1% units, -110 average price, a 54% win rate, ten bets a week for eighteen weeks. That is 180 bets of $20, so $3,600 of turnover.

Edge = (0.54 × 0.9091) − 0.46 = 0.4909 − 0.46 = 0.0309, or 3.09% on turnover.

Profit = $3,600 × 0.0309 = +$111.27, finishing at $2,111.27.

A 54% win rate at -110 is a strong, professional-grade result. It returns 5.6% on the bankroll over a season at 1% units. That is the honest scale of the thing, and it is why the fastest route to a bigger number is more bankroll or more volume rather than a bigger unit.

The Band Matters More Than The Line

The single figure is an average across thousands of imaginary seasons. Any one season is a draw from a wide distribution, and the width is the part people underestimate.

For the example above, one standard deviation across 180 bets is about $268. So the ordinary range of outcomes is roughly −$157 to +$379, and one season in three lands outside even that. A genuinely 54% bettor can finish a full season down money without anything having gone wrong.

Which is the practical lesson: a losing season does not refute an edge, and a winning season does not prove one. At this sample size the noise is bigger than the signal, which is exactly why process measures like closing line value are worth more than the profit column until the sample gets large. Sample size covers how large that is.

Flat Versus Percentage Staking

Flat staking fixes the unit at the start of the season. Percentage staking recalculates it from the current bankroll, so stakes rise as you win and fall as you lose.

Percentage staking compounds and is, in the long run, mathematically superior for a bettor with a real edge — it is a mild form of Kelly. It also has a defensive property that matters more: after a drawdown the stakes shrink automatically, so a losing run cannot bankrupt you the way a fixed stake against a shrinking bankroll can.

Flat staking wins on simplicity and legibility. The unit does not change mid-season, a record in units is directly comparable across months, and there is no arithmetic to do before every bet. For most bettors, correctly executed flat staking beats imperfectly executed percentage staking.

Switch the method in the calculator and the difference over a single season is usually small — a few percent of the bankroll. It compounds meaningfully over years, not weeks. The flat betting versus percentage guide covers the choice in detail.

Using It Honestly

The projection is only worth what the inputs are, and there are three ways to lie to yourself with it.

The win rate. Put in your actual recorded rate, not the one you hope for. If you have never tracked it, run the projection at 52.38% — break-even at -110 — and see what the plan does with no edge at all. That is the correct baseline until a real number exists, and the bet tracking guide covers how to get one.

The average price. Bettors quote -110 and bet at -118 after chasing numbers and dabbling in props. Two points of price is worth more than most people's entire edge, so use the average you actually get.

The volume. More bets multiply a positive edge and a negative one alike. If the edge is negative, higher volume is simply a faster way to reach zero, which the calculator will show you plainly.

Set the unit with the unit size calculator first, then project. If the projected outcome looks too small to bother with at a sane unit size, the answer is a larger bankroll or a longer horizon, not a larger stake.

Frequently Asked Questions