How to Calculate Unit Size and Manage Risk in Sports Betting

Your unit size is the most important number in your betting, more important than any single pick. Set it too high and a normal losing streak can wipe you out. Set it sensibly and you give your edge time to show up. This guide walks you through calculating a unit, stress-testing it and adapting it to the rules of a funded challenge.

What is a unit?

A unit is your standard stake, expressed as a percentage of your bankroll. Talking in units rather than dollars lets you compare results fairly across bankroll sizes and keeps your staking consistent. If your unit is $50 and you are up 12 units, you are up $600.

Step 1: Define your bankroll

Your bankroll is the money set aside only for betting, an amount you could lose without affecting your bills, savings or wellbeing. In a funded challenge, the account size plays this role for staking purposes, while your real cost is the challenge fee.

Step 2: Choose a percentage

Most disciplined bettors use between 1% and 3% of their bankroll per unit. As a rough guide:

• 1%: conservative. Ideal for challenges and for anyone still proving their edge.
• 2%: moderate. Common among experienced bettors with a tracked record.
• 3%: aggressive. Only sensible with a well-established edge and a high tolerance for swings.
• 5% or more: very high risk. A modest losing streak can do serious damage.

Step 3: Calculate the unit

Unit = bankroll × percentage

With a $2,000 bankroll at 1.5%, your unit is $30. On a $10,000 challenge account at 1%, it is $100.

Step 4: Stress-test against losing streaks

Losing streaks are not a sign that something is wrong; they are a normal part of betting. A rough rule for the longest losing streak you should expect over n bets is:

Longest streak ≈ ln(n × win rate) ÷ ln(1 ÷ loss rate)

For a bettor who wins 55% of picks, that works out to about seven losses in a row over 500 bets and about eight over 1,000. A 50% bettor should expect eight or nine.

Now see what eight straight losses costs at different unit sizes, using flat stakes:

• 1% unit: 8% drawdown
• 2% unit: 16% drawdown
• 3% unit: 24% drawdown
• 5% unit: 40% drawdown

And that is just one streak. Real drawdowns often come from several bad runs close together. If the numbers above make you uncomfortable, your unit is too big.

Step 5: Decide how to stake favorites and underdogs

There are two common approaches:

• Risk one unit: you always stake one unit, whatever the odds. Simple and consistent.
• To win one unit: on favorites, you stake enough to win one unit, so at −150 you would risk 1.5 units. This keeps profits even but increases risk on heavy favorites.

For challenges, “risk one unit” is usually safer, because it keeps your maximum loss per pick predictable.

Step 6: Resize on a schedule

Recalculate your unit weekly or monthly, not after every bet. If your bankroll grows 20%, your unit grows with it; if it falls, your unit shrinks, which naturally protects you during a downswing.

Fitting your unit to a funded challenge

Funded challenges add hard limits, so your unit has to fit inside them with room to spare. Here is how the numbers look on BetFunder’s 1-Phase challenge, which has a 15% maximum overall loss and a 10% maximum daily loss:

• $5,000 account: stake range $20 to $100. A 1% unit is $50, giving you 15 units before the overall limit and 10 units before the daily limit.
• $10,000 account: stake range $25 to $200. A 1% unit is $100, again 15 units of overall room.
• $25,000 account: stake range $50 to $500. A 1% unit is $250.
• $50,000 account: stake range $100 to $1,000. A 1% unit is $500.

A useful rule of thumb is to keep at least 12 to 15 units of room between your starting balance and the maximum overall loss. At a 1% unit on a 15% limit you have 15; at 2%, you have only 7.5, which a single bad week could exhaust. On 2-Phase and 3-Phase challenges, the 20% overall limit gives you a little more room.

Managing risk beyond the unit

• Personal daily stop: stop for the day after losing 3 to 4 units, well inside the platform’s daily limit.
• Exposure cap: limit the total units you have riding at one time, for example five.
• Correlation check: count a side, total and player prop from the same game as linked exposure, not three separate bets.
• Confidence tiers, used sparingly: if you vary stakes, keep it to a narrow band such as 0.5 to 1.5 units and set the rules in advance.

For more on staking methods, including fractional Kelly, see our bankroll management strategies.

Quick reference

• Unit = bankroll × 1% to 3%
• Assume streaks of eight or more losses will happen
• Keep 12 to 15 units of room before any loss limit
• Recalculate on a schedule, not after every bet
• Set a personal daily stop well inside the platform limit

See the exact stake ranges and loss limits for each account in the configurator on our Challenges page.

BetFunder challenges use virtual Profit Points and are available only to people who meet our eligibility requirements. Only spend what you can afford on a challenge fee. If betting stops being fun, visit our Responsible Gambling page.