A bonus is not free money, and it is not a scam either. It is a trade: the operator gives you extra balance, and in exchange you agree to put a defined amount of money through the games before any of it can be withdrawn. Whether that trade is worth taking is an arithmetic question, and the arithmetic is not hard once you know which numbers to pull out of the terms.
This guide shows you how to calculate the expected cost of a bonus in NZD, and which clauses change that number the most.
The two numbers that set the size of the task
The multiplier is the headline: 30x, 35x, 40x. What it multiplies is the part people miss.
- Bonus only (B): a NZD 100 bonus at 35x means NZD 3,500 of turnover.
- Deposit plus bonus (D+B): the same 35x applied to a NZD 100 deposit and a NZD 100 bonus means 35 x 200 = NZD 7,000 of turnover.
Identical headline, double the work. A 30x D+B offer is worse than a 40x B offer on the same amounts (NZD 6,000 versus NZD 4,000), so the multiplier alone tells you very little. Always find the phrase that says what is being multiplied before comparing two offers.
Turnover is not the cost
Here is the part that changes how people read bonuses. Putting NZD 3,500 through a pokie does not cost NZD 3,500. Each spin returns most of the stake on average, and what you actually lose across the whole requirement is roughly:
Expected cost = total turnover x house edge
House edge is simply 100% minus the game’s RTP (return to player). A pokie with 96% RTP has a 4% edge. So:
- NZD 3,500 turnover at a 4% edge = NZD 140 expected loss
- NZD 7,000 turnover at a 4% edge = NZD 280 expected loss
Now the comparison is honest. A NZD 100 bonus that costs NZD 140 in expected losses to unlock is, on average, a losing trade. The same bonus at 20x bonus only (NZD 2,000 turnover, NZD 80 expected cost) is, on average, a winning one. Nothing about the offer changed except one number in the terms.
Run that calculation before you opt in and most bonus decisions make themselves.
Game weighting quietly multiplies the requirement
Weighting decides how much of each dollar you stake counts towards the requirement. Pokies are typically 100%. Table games are commonly 10%, sometimes 5%, sometimes zero.
At 10% weighting, NZD 1 wagered contributes 10 cents. To clear a NZD 3,500 requirement on a game weighted at 10%, you must wager NZD 35,000.
That sounds ruinous, but the house edge on those games is usually far lower, so the two effects partly cancel:
| Route | Turnover needed | Typical edge | Expected cost |
|---|---|---|---|
| 96% RTP pokie, 100% weighting | NZD 3,500 | 4% | NZD 140 |
| 99% RTP table game, 10% weighting | NZD 35,000 | 1% | NZD 350 |
Partly, not fully. Low-edge games are usually weighted low because they are low-edge, and the weighting is generally set so the operator does not lose on the exchange. The practical rule: check the weighting table, then run the turnover-times-edge sum for the game you actually intend to play. Do not assume the low-edge game is cheaper.
The same logic applies within pokies. A 94% RTP game costs half again as much to clear the same requirement as a 96% one. RTP is published in the game’s info panel, and some titles ship at different RTP settings at different operators, so check the panel rather than a third-party listing.
The clauses that decide whether you finish at all
Turnover maths tells you the average cost. These terms decide whether you get to the end.
Max bet while wagering. Usually NZD 5 to NZD 10 per spin or hand. Exceed it once, even accidentally on an autoplay setting, and most operators will void the bonus and everything won with it. This is the most common reason a cleared bonus does not get paid.
Time limit. Seven days is common, 30 days is generous. Divide the turnover by the days: NZD 7,000 over seven days is NZD 1,000 a day. If that is more than you would normally play, the limit is the binding constraint, not the multiplier.
Max cash-out. A cap such as 5x the bonus means a NZD 100 bonus can never return more than NZD 500 no matter what you hit. Caps are what make large-multiplier “big” bonuses mathematically small.
Excluded games. Play an excluded title with bonus funds and the bonus typically voids. The exclusion list changes, so read it on the day.
Bet sizing versus volatility. Two restrictions can conflict: a max bet that keeps stakes low and a time limit that requires high turnover. Where they conflict, the offer is not really designed to be cleared.
Sticky versus non-sticky. A non-sticky bonus keeps your own deposit separate, so you can withdraw your cash balance and walk away from the bonus. A sticky bonus merges the two and locks everything until the requirement is met. Non-sticky is meaningfully better and rarely advertised as such.
Variance: why your result will not be the expected cost
Expected cost is the average of a distribution, not a forecast. Clearing NZD 3,500 on a high-volatility pokie might leave you NZD 600 down or NZD 900 up; the NZD 140 figure is what you would converge towards across many attempts. Low-volatility games track the average more closely, which is why they are the sensible choice if your goal is simply to clear a requirement with the fewest surprises.
Do not read variance as a reason to ignore the maths. It is a reason to size your play so that a bad run inside the normal range does not matter to you.
Real NZ casino bonuses: how the maths compares
The table below applies the same calculation to actual offers from reviewed casinos. Figures use a NZ$200 deposit with a matched bonus at the stated multiplier, and a 96% RTP pokie (4% edge).
| Casino | Bonus on NZ$200 deposit | Wagering | Turnover required | Expected cost |
|---|---|---|---|---|
| Cashy | 25% cashback (no match) | 0× | NZ$0 | NZ$0 — paid as real cash on net losses |
| Bitdreams | NZ$200 (100% match) | 1× | NZ$200 | ~NZ$8 expected cost |
| BitStarz | NZ$200 (100% match) | 40× | NZ$8,000 | ~NZ$320 expected cost |
| FastPay Casino | NZ$200 (100% match) | 50× | NZ$10,000 | ~NZ$400 expected cost |
The expected cost column is what the house edge takes from your turnover on average. At 1× wagering (Bitdreams), clearing a NZ$200 bonus costs around NZ$8 in expected losses — less than a coffee. At 50× (FastPay), the same bonus costs ~NZ$400, roughly double the bonus value. The wagering multiplier is the single biggest lever in any bonus decision.
Use our bonus calculator to cost any specific offer before claiming.
A checklist that takes two minutes
- Find the multiplier and whether it applies to B or D+B. Calculate the turnover in NZD.
- Find the weighting for the game you will play. Divide the turnover by that weighting.
- Find the RTP of that game. Multiply the turnover by 100% minus the RTP.
- Compare that expected cost with the bonus amount. If it is higher, the offer is negative for you.
- Check max bet, time limit, max cash-out and excluded games. Any one of these can turn a positive offer negative.
- Decide before you deposit, and screenshot the terms as they stood when you accepted them.
If the terms are not clear enough to complete steps one to three, that is the answer. A bonus you cannot cost is a bonus you should not take. Our guide to how New Zealand gambling law applies explains why documenting the terms you agreed to matters if a payout is ever disputed, and if bonus chasing has stopped being fun, the free support services on our responsible gambling page are worth a look.
Q: How do I calculate a wagering requirement?
A: Multiply the requirement by whatever it applies to. A 35x requirement on a NZD 100 bonus alone is NZD 3,500 of turnover; the same 35x on deposit plus bonus with a NZD 100 deposit is NZD 7,000. Then divide by the game weighting, since a game weighted at 10% needs ten times the turnover to count the same.
Q: What does a wagering requirement actually cost me?
A: Roughly the turnover multiplied by the game’s house edge, which is 100% minus its RTP. Clearing NZD 3,500 on a 96% RTP pokie costs about NZD 140 in expected losses. If that figure is larger than the bonus itself, the offer is negative value on average.
Q: Is 35x wagering good or bad?
A: It depends entirely on what it multiplies and which games count. 35x on bonus only, with 100% pokies weighting and a 30-day window, is workable. The same 35x on deposit plus bonus with a seven-day limit and a max cash-out cap is a far worse deal despite the identical headline number.
Q: Why do table games count less towards wagering?
A: Because their house edge is much lower. Weighting them at 10% keeps the operator’s expected margin roughly consistent across games. It does not automatically make them cheaper to clear on, so run the turnover-times-edge calculation for the specific game before choosing.
Q: What happens if I break the max bet rule?
A: Most operators void the bonus and any winnings derived from it, even when the breach was a single accidental spin or an autoplay setting left too high. It is the most common reason a fully wagered bonus never gets paid out, so confirm the limit before your first spin.