Bankroll & Budget Calculator

Before you play, it pays to know how far your money will realistically stretch. This calculator takes your bankroll, your bet size, and the game you're playing, then simulates thousands of sessions to estimate how many rounds you'll typically last, how likely you are to lose the lot, and what you can expect to be left with.

We've framed this tool around playing within your means, not chasing wins. Treat the number you enter as money you're genuinely comfortable losing — entertainment spending, not an investment. Used this way, the calculator becomes a planning aid: it helps you pick a bet size that matches how long you want to play and shows you, honestly, what the odds look like.

Expected rounds your bankroll lasts is the median session length across the simulations — half of sessions run longer, half end sooner. Chance of losing the lot is the percentage of simulated sessions where your balance hit zero before you reached your round limit or win target. Expected loss is the average amount gone by the end, which over time tracks the game's house edge. The typical balance at the end shows where a middling session finishes. If the risk of ruin looks higher than you're comfortable with, lower your bet size or shorten your session — both push the numbers in a safer direction.

Bet sizing: the lever you actually control

You can't change a game's house edge, but you fully control how fast you expose your bankroll to it. Bet size is the single biggest lever you have. As a rough guide, keeping each bet to around 1% of your bankroll lets you ride out the inevitable cold streaks; betting 10% or more at a time means a short run of bad luck can wipe you out before variance has any chance to swing back.

There's a direct trade-off between session length and excitement. Bigger bets mean bigger swings and a shorter average session; smaller bets stretch your entertainment further but with calmer ups and downs. Neither is wrong — but deciding deliberately beats drifting into bets that are bigger than you meant to make.

Setting stop-losses and win targets

A stop-loss is a line you draw in advance: if your balance falls to this point, you walk away. A win target does the same on the upside — bank the profit and stop. Both work because they replace in-the-moment decisions, made when you're up or tilted, with a plan you set while thinking clearly. The calculator lets you test how different limits change your outcomes.

No staking system beats the house edge over time — not Martingale, not any progression. Chasing losses by doubling up feels logical but simply concentrates your risk into rarer, larger losses. The honest purpose of a bankroll plan isn't to manufacture profit; it's to keep your play affordable and enjoyable. If gambling stops feeling like entertainment, the Gambling Helpline is free and available 24/7 on 0800 654 655.

Worked example: NZ$100 on the pokies

You sit down with a NZ$100 bankroll and play a pokie with a 96% RTP (a 4% house edge), betting NZ$1 a spin. You haven't set a stop-loss or win target — you just want to know how long NZ$100 lasts.

The simulation typically shows the bankroll lasting around 250–350 spins before it's gone, with an expected loss over a long session that tracks the 4% edge. If instead you drop your bet to NZ$0.50 a spin, the expected number of rounds roughly doubles and your chance of busting within any fixed time falls sharply — the same NZ$100 simply buys more entertainment. Add a NZ$60 stop-loss and you cap the damage at NZ$40 in most sessions, at the cost of occasionally ending a session that might have recovered. The lesson: small changes to bet size and limits move the numbers a lot, and you control both.

Glossary

RTP

Return to player — the percentage of all wagered money a game pays back over the very long run; a 96% RTP returns NZ$96 per NZ$100 staked on average.

House edge

The casino's built-in mathematical margin on each bet, equal to 100% minus the RTP; a 96% RTP means a 4% house edge.

Volatility

How a game delivers its returns — low volatility means frequent small wins, high volatility means rare but larger wins and a bumpier ride.

Wagering requirement

The number of times you must bet a bonus (or deposit plus bonus) before winnings can be withdrawn, shown as a multiplier like 35x.

Expected value (EV)

The average outcome of a bet or bonus across thousands of repetitions — a guide to the long-run average, not a prediction for any single session.