Every unit-sizing rule starts with "bet 1 to 2% of your bankroll," and that's no use until you know what the bankroll is. Most people starting out with player props skip that question. They deposit whatever feels right on a Sunday and work backward from the bet size they'd like to make. This page gets you to a real number: written down, matched to how often you bet, and sitting in an account of its own.

Count in units, then in dollars

A bankroll is money set aside only for betting, kept apart from what you spend on everything else. A unit is your standard stake on one bet. Whether a bankroll is big enough has nothing to do with how many dollars are in it. What matters is how many units it holds.

The usual guideline is a minimum of 50 to 100 units. That's the range the TopEndSports bankroll calculator works from, using the formula Bankroll = Unit Size × Number of Units. So if you want to bet $50 a play, you need $2,500 to $5,000 behind it. If you can only put up $1,000, your unit is $10 to $20, whatever you'd like it to be.

The reason for counting in units is variance, and the numbers are bigger than most beginners expect. In its player props series, Wizard of Odds works through 100 bets of $100 at -110 by someone who really does win 55% of the time. The expected profit is $500, but the standard deviation is $950. Roughly two times in three, that bettor ends up somewhere between down $450 and up $1,450. At the bad end of the 95% range they're down about $1,362, which is close to 14 units, and there's about a 30% chance they're behind after 100 bets even with a real edge. If your bankroll is 20 units, that ordinary bad stretch takes most of it.

The strongest objection to all this comes from Kelly betting. That approach sizes each bet from your edge, so the total doesn't need its own rule. Wizard of Odds puts the deeper version bluntly:

Bankroll management won't make you a winning bettor if you don't have positive EV.

Joey Shackelford
Author, The Mathematics of Player Props, Wizard of Odds

That's true, and it's the right way to think about it once you know your edge. A beginner doesn't. The same series shows that a win-probability estimate built from 50 games carries a 95% confidence interval of plus or minus 13.9%, and it advises that when your estimate is that loose, you should bet smaller or not at all. Until you have a few hundred tracked bets, you don't have an edge you can feed into a formula. What you can do is hold enough units to find out.

What to have in hand first

None of this costs money to set up. What it takes is honest arithmetic and somewhere to keep records.

  • Your monthly money after essentials

    What's left once rent, bills, savings and necessities are paid. That's the budget rule behind the American Gaming Association campaign covered by Action Network.

  • A rough count of your bets per week, and which sports

    Several NBA props a night needs a different bankroll from a handful of NFL receiving yards bets on Sundays.

  • A home for the money

    Funded sportsbook accounts used for nothing else. SI's example splits a $2,000 bankroll across two books so you can shop lines.

  • A way to log every bet

    The amount, bet type, odds and result, as VSiN recommends. A spreadsheet works, and so does a tracker.

Setting the number

One warning before the steps. No source here gives a percentage of income to put into a bankroll. VSiN deliberately doesn't name a dollar figure and says only to use money you can afford to lose. So your monthly income gives you a ceiling, not a formula. That's honest, but it means the steps below cap the bankroll from above and set a minimum unit count from below. You pick the number between them.

  1. Write down your loss ceiling

    Pick the amount you could lose in full without touching rent, bills or savings. DeucesCracked says that for beginners this is often just a few hundred dollars. What you should see: one dollar figure that you could watch go to zero without having to change anything else in your month.

  2. Choose a unit count for the sports you bet

    TopEndSports scales the count with how often you bet and how swingy the sport is: 75 to 100 units for the NFL, 100 to 150 for the NBA and NHL, and 150 to 200 for MLB's 162-game season. Props are noisy and the books' hold on them is real (Wizard of Odds puts it at 4 to 6% on major props and 10 to 15% or more on niche ones), so go to the top of the range. If you bet more than one sport, use the highest count. What you should see: a single number, probably 100 or more.

  3. Divide to get your unit

    Unit = bankroll ÷ unit count. What you should see: a stake of 1% of the bankroll or less. If the result is smaller than you hoped, the arithmetic is working.

  4. Check it against your volume

    Multiply your bets per week by the weeks in a season. If that's past 100 bets, remember the Wizard of Odds range: a bettor with an edge can be down around 14 units at the bad end. What you should see: that drawdown leaves well over three-quarters of your bankroll intact.

  5. Move the money and lock it

    Fund the betting accounts and nothing else. Set a deposit limit where your book offers one; Action Network lists deposit and wagering limits, cooling-off periods and self-exclusion among the tools operators provide, though what's available varies by state and platform. What you should see: bankroll money that's no longer in your checking account.

  6. Decide your rules for a bad run now

    Recalculate the unit once a month from the current balance, not every night. TopEndSports suggests treating a 20% drop as a point to stop and reassess. What you should see: both rules written down before your first bet.

An NBA props bettor with $250 a month to spare

Say you have $250 a month left after essentials, you bet about six NBA player props a week, and you'd like to bet $50 a play. You've already put aside $1,500 you could lose without it hurting.

Unit count for NBA props (top of the 100 to 150 range)150 units
Bankroll needed for a $50 unit$7,500
Months of spare money to save that30 months
Bankroll you actually have$1,500
Unit that bankroll supports ($1,500 ÷ 150)$10
Bets per season at six a weekabout 100 in four months
Bad-end drawdown from the Wizard of Odds range (about 14 units)about $140, under 10% of the bankroll

The $50 unit is two and a half years of saving away. The $10 unit is affordable today and survives a poor run with plenty to spare. Start at $10, and let results earn you the bigger stake rather than an income you'd have to raid.

Where first bankrolls break

Working backward from the bet you want. This is the most common mistake, and the worked example above shows it. You'll know it's happened if funding the account means trimming rent or bills, or if your unit is more than 2% of the balance. The fix is to make the unit smaller, never the unit count.

Too few units to survive. DeucesCracked works through a 10-bet losing streak, which happens over thousands of bets even at a 55% win rate. At 5% stakes it takes about half the bankroll once you count the juice. At 1% stakes it takes about a tenth. If one cold weekend has you down a quarter of your money, your bankroll was 20 units pretending to be 100. Rebuild at the smaller unit. The cold stretch itself has its own playbook.

Topping up after losses. A second deposit in the middle of a month to win it back is chasing, and every source here, from SI to the AGA guidelines, warns against it. The tell is that your deposits stop matching the figure you set in step one. Stop, recalculate from what's actually left, and carry on at the new unit.

Raising stakes after a hot week. SI calls this "house money" thinking and says it usually hands the winnings back faster. One rule of thumb from Bookmaker100 is to wait for at least 200 bets with a positive ROI, then raise the unit by no more than 25 to 50% at a time. Twelve good nights don't count as evidence.

Once the money is set aside

With the bankroll funded, the next question is what each bet should risk. That means choosing between flat units and a fraction of Kelly, and deciding how much tighter to go on high-variance prop markets. All of that is covered in setting a unit size. If you're still unsure whether your betting money counts as separate from everyday cash, the page on what a bankroll is settles it.

To see how your number might hold up over a season, run it through the bet sizing and losing streak calculator. It simulates a thousand seasons from your unit and volume and shows the losing streak you should expect.

Questions at the starting line

Yes, as long as you accept a $1 unit. At 100 units, a $100 bankroll means $1 bets. DeucesCracked notes that beginners often start with just a few hundred dollars. A small bankroll is fine. A small bankroll with $20 bets on it isn't.

None of the sources here give one. The consistent rule is to use only money left over after rent, bills, savings and necessities. Treat that leftover amount as the most you could put in, not as a target to hit.

At least 50 to 100, and more for higher-volume sports. TopEndSports suggests 75 to 100 for the NFL, 100 to 150 for the NBA and NHL, and 150 to 200 for MLB. Prop bettors should sit at the top of whichever range applies.

Add new money only as a planned decision, never in the middle of a losing run. Let your unit grow when the balance does, by recalculating once a month. Before raising your stakes on purpose, Bookmaker100 suggests waiting for 200 bets with a positive ROI.

The National Council on Problem Gambling runs the National Problem Gambling Helpline at 1-800-MY-RESET. You can call, text or chat through 1800myreset.org, and it connects you with resources in your state.