How to Calculate Your Unit Size and Bet Amount

To calculate a betting unit, multiply your chosen bankroll by your unit percentage and divide by 100: U = B × r / 100. Your stake is m × U, where m is the number of units. With a USD 1150 bankroll and a 1% unit, one unit is USD 11.50.

Here, B is your bankroll, r is your chosen percentage, and U is the cash value of one unit. All cash examples below use USD to match the embedded calculator. The arithmetic works with any currency; just do not mix currencies within a calculation.

What is a betting unit, and how many units are in a bankroll?

A unit is your chosen reference stake, not necessarily 1% of your bankroll. To express your bankroll in units, calculate B / U.

For a USD 1150 bankroll:

If you choose a cash unit of USD 11.50, convert units to money as follows:

These are conversion tables, not risk recommendations. There is no universally safe percentage. For more on choosing a percentage, see what percentage of your bankroll to bet.

How should you define your bankroll before calculating units?

Your bankroll is a dedicated, affordable betting budget left after essential expenses—not all the money in your accounts. Exclude money needed for housing, food, bills, and other essentials, as well as borrowed funds.

First, write down what your bankroll calculation includes. For example, you might use uncommitted betting funds allocated across several accounts plus the stakes tied up in open bets. Under that definition, count each open stake once: do not add it again if the balance you are using already includes it. Do not add hypothetical payouts from unsettled bets.

Keep these two figures separate:

• Your bankroll basis: the funds included under your stated calculation rules.
• Cash available for a new bet: the uncommitted money you can actually stake now.

Open stakes may count toward the first figure without being available for another bet. A restricted bonus is not unrestricted cash either.

Deposits and withdrawals change your budget but are not betting net profit or loss. Record them separately. Set a firm spending limit and a stop-loss—the amount of losses at which you stop betting—in advance. Do not expand the budget to chase losses.

GambleAware's budgeting guidance offers practical help with affordable spending. For the broader concept, start with what bankroll management means.

Should you keep the cash unit fixed or recalculate it?

With flat betting, also called level staking, your cash unit stays constant until a declared reset; with proportional staking, it is recalculated from your current bankroll. The methods are not identical just because both start at 1%.

In this example, the fixed stake is USD 11.50. It does not automatically shrink after losses. With proportional staking, you update your bankroll after bets settle and calculate 1% of that new balance.

If all n bets lose:

• Fixed stake: B − nU
• Proportional stake: B × (1 − r / 100)ⁿ

All balances are in USD. Proportional-staking balances are displayed to the nearest cent. Before display rounding, the balances are USD 1040.03938626 after 10 losses and USD 940.59297824 after 20.

After 10 losses, the fixed USD 11.50 unit is 1.1111% of the remaining USD 1035, even though it started at 1%.

This is an all-loss calculation with no wins, deposits, withdrawals, fees, stake rounding, or minimum-bet restrictions. It is not an empirical simulation and does not estimate the probability of a losing streak. The chart shows a decline from the starting bankroll, not drawdown from a previous peak.

A fixed stake equal to 5% of the starting bankroll exhausts it after 20 such losses. Proportional staking does not reach zero in a finite number of bets in this ideal model, but a practical minimum stake can prevent further betting sooner.

Set your fixed-unit reset schedule ahead of time—for example, monthly or when your bankroll reaches a declared change threshold. There is no universal rule requiring a reset after a 25% change. The staking plan calculator can help organize a broader plan and its limits.

How do you calculate bets of 2, 3, or 5 units?

Multiply your cash unit by the number of units; this changes the stake, not your bankroll definition. With U = USD 11.50, a 3-unit bet is USD 34.50, or 3% of the reference bankroll. A 5-unit bet is USD 57.50, or 5%.

Subjective confidence in a pick is not a measured win probability. Feeling more confident does not, by itself, justify increasing a stake from 1 unit to 3 or 5 units.

Set separate limits for a single bet and total open exposure. Five open bets of 2 units each total 10 units, or USD 115—10% of the USD 1150 reference bankroll. If their outcomes depend on the same event or shared factors, they are not independent. Equal total stakes do not necessarily mean equal risk.

ToolsGambling localhost screenshot showing tiered staking and a 3-unit stake with a USD 1150 bankroll

Localhost interface screenshot: 3 units at USD 11.50 per unit produce a USD 34.50 stake.

How do you use the betting unit calculator?

Enter your bankroll and unit percentage, then read the cash amount for your chosen number of units. The calculator multiplies the entered bankroll by the percentage; it does not track your accounts or betting results.

To reproduce the example:

1. Enter 1150 in the bankroll field.
2. Select “Fixed unit (flat %)”.
3. Enter 1 in the percentage field.
4. Check the amounts: 1u = USD 11.50, 2u = USD 23, 3u = USD 34.50, and 5u = USD 57.50.
5. To view the tiered example, switch to “Confidence-weighted (tiered)” and select “3u — best bet”. The stake is USD 34.50.

Those interface labels identify the controls; they do not establish confidence or endorse a bet as the best choice.

ToolsGambling localhost screenshot showing the fixed-unit calculation for a USD 1150 bankroll and a 1% unit

Localhost interface screenshot: one unit is USD 11.50. The tool's display currency is fixed to USD.

Both the fixed and proportional settings use the same arithmetic: entered bankroll × percentage. For proportional staking, manually enter the new balance after bets settle. The tool does not maintain account balances or a betting history.

The risk badges are not measured probabilities of ruin and do not promise bankroll growth. The footer's suggestion to recalculate after a 25% change is a heuristic, not a mandatory rule.

The embedded “YOUR EDGE” field adds the entered number of percentage points to a 50% probability. It is not a general-purpose edge input. For Kelly sizing, use the separate Kelly calculator with a probability input.

How is the Kelly criterion different from a standard unit?

The Kelly criterion sizes a bankroll fraction from probability and odds rather than defining a constant unit. Its theoretical basis is long-term capital growth within a specified model, described in J. L. Kelly's original 1956 paper.

For a binary win/loss cash bet with known probability p, decimal odds D, and no extra costs:

f = max(0, (pD − 1) / (D − 1))

Stake = B × Kelly fraction × f

Using hypothetical p = 55%, D = 1.91, and B = USD 1150:

Quarter Kelly means 25% of the full Kelly stake, not 25% of your bankroll. The 5.05% edge is expected net return per amount staked, not five percentage points above 50%.

Formula from Kelly's 1956 paper, page 919: V_N = (1+l)^W(1−l)^L V_0

Page 919 of the 1956 paper, shown in the linked hosted retypeset copy. Here, ℓ is the fraction of capital staked; W and L are the counts of wins and losses, respectively; V₀ is the starting capital; and V_N is the capital after N bets. This formula assumes even-money wins and losses; it is not the direct formula for D = 1.91. The paper uses p and q differently.

Avoid this method if your probability estimate is uncalibrated. Confidence cannot substitute for p. Kelly sizing neither guarantees profit nor provides a universally optimal real-world stake.

How should you handle rounding and minimum bets?

Round down to a permitted stake increment and record the actual bankroll percentage at risk. A minimum bet does not become one unit simply because you cannot stake less.

With a USD 1150 bankroll:

• 1150 × 1% = USD 11.50
• Rounding down to USD 11 makes the stake 0.95652% of the bankroll.
• A USD 25 minimum is 2.17391% of the bankroll, or 2.17391 units, not 1 unit.

If the minimum exceeds your limit, skip the bet or choose an available option with a genuinely lower minimum. Do not increase the bankroll or deposit more money to make the calculation fit.

Rounding changes the amount at risk, not the odds or the bet's edge.

Is risking one unit the same as winning one unit?

“Bet 1 unit” usually means risk one unit, not target one unit of net profit. Confirm the convention before placing or recording a bet.

Decimal odds express gross return divided by stake, including the returned stake. On a win, net profit is S × (D − 1), where S is the stake. On a loss, net profit is −S. On a push, it is 0, assuming the settlement rules impose no additional deductions.

Do not treat exact American odds of −110 and rounded decimal odds of 1.91 as identical:

If you risk USD 11.50 at decimal odds of 1.91, a win produces USD 10.465 in net profit, or USD 10.47 when rounded to cents. A loss produces −USD 11.50; a full push produces 0. The sportsbook's settlement rules determine the actual rounding.

How do you calculate results in units and yield?

Add each bet's net profit, then divide by turnover—the total amount staked—to calculate yield. For unit-based records, define the cash value of the unit before placing each bet.

Here is a three-bet ledger using one unchanged unit:

Repeat the calculation in three steps:

1. Add the results: 0.91 − 2 + 0 = −1.09 units.
2. Add the stakes, including the pushed bet: 1 + 2 + 0.5 = 3.5 units of turnover.
3. Divide net profit by turnover and multiply by 100: −1.09 / 3.5 × 100 = −31.142857%, rounded to −31.14%.

This is yield, not return on the starting bankroll. Its denominator is total stakes, not the original USD 1150.

At USD 11.50 per unit, total net profit before intermediate settlement rounding is −USD 12.535. Actual cash results can differ if each bet's settlement is rounded separately, so the unit ledger is clearer for this example.

Record these fields for every bet:

Keep deposits and withdrawals separate. If your cash unit changes, do not multiply your entire historical unit total by today's U. Calculate cash results using the unit value that applied to each bet.

A claim of “up X units” does not prove skill without turnover, sample size, and clear stake conventions.

What should you check before your next bet?

Declare your bankroll basis, unit size, and limits before placing the bet, then round the stake and record it. This short checklist helps keep individual picks from changing your rules:

• Define your bankroll and distinguish available cash from open stakes.
• Choose your reference percentage and cash unit.
• State the method: a constant cash stake or a percentage of the current bankroll.
• Set a reset schedule, a total open-exposure limit, and a stop-loss.
• Check the minimum and stake increment, round down, and record the actual risk.
• Save the odds, stake, and cash unit; record net profit after settlement.

Smaller stakes do not create positive expected value or guarantee a particular amount of playing time. Calculating risk of ruin also requires a time horizon, a critical bankroll threshold, probabilities, payouts, and a staking model—not just a unit size. For the broader process, see the bankroll management guide.