Wagering calculator: what a casino bonus really costs

By the Rootan NZ team· Checked 14 October 2026

A bonus is only "free" once you have met its wagering requirement. Enter the terms below to see how much you would need to bet, and the expected loss from the house edge while you do it.

Bonus amount (NZ$)Your deposit (NZ$)Wagering requirement (x)Wagering applies toGame RTP (%)Game contribution to wagering (%)

Total you need to bet$1,000.00

Wagering counted towards the requirement$1,000.00

Expected loss while wagering (house edge)$40.00

Bonus minus expected loss$60.00

Example: a $100.00 bonus with 10x wagering on the bonus only means $1,000.00 of bets. At 96% RTP the expected loss is $40.00, so the bonus is worth about $60.00 on average. Turn on JavaScript to change the numbers.

How the numbers are worked out

Wagering counted = (bonus, or deposit + bonus) × the wagering multiple. If a game only counts part of each bet — say 10% for table games — you need to bet more: total bets = wagering counted ÷ contribution. The expected loss is total bets × (1 − RTP). The calculator uses the open-source rootan-probability library.

What the calculator leaves out

It shows an average, not what will happen in one session. You can lose your whole balance before you finish wagering, especially on high-volatility pokies. It also ignores maximum-cash-out caps, bet limits and expiry dates — read the full terms before you accept any bonus. New Zealand's new rules cap bonuses at licensed casinos — see bonuses and inducements.

A quick rule of thumb

The higher the multiple and the lower the game contribution, the more a bonus costs. When "bonus minus expected loss" turns negative, the bonus is expected to cost more than it gives. If you notice you are betting more to "unlock" money, stop and see our safer gambling help.