Compare the cap rather than the percentage, convert free spins into a cash figure, then work out the total stake each offer demands before anything can be withdrawn. The offer with the largest headline is frequently the one that costs the most to clear.
Step one: read the cap, not the percentage
A match percentage without its maximum is marketing rather than information. 325% up to £50 hands you at most £50. 100% up to £500 hands you up to £500. The larger-looking offer is ten times smaller.
The cap also tells you the deposit needed to use the offer in full — a 100% match up to £500 requires £500 of your own money to max out, which may be far more than you intended to deposit.
Step two: put a number on the free spins
Free spins are quoted as a count, which is meaningless until you know what each spin is worth. Two hundred spins at 10p is £20. Fifty spins at £1 is £50.
Then check what the winnings become. Spin winnings paid as bonus funds are subject to wagering; paid as cash they are not, which is a large difference in real value and is always specified in the terms.
Step three: calculate the turnover each offer demands
This is the step that reorders most comparisons. Multiply the requirement by its base, and compare the totals rather than the bonus amounts.
Hypothetical: two offers on a £100 deposit
- Offer A
- 200% up to £200, 45x on deposit + bonus
- A — bonus received
- £200
- A — total stake required
- 45 × £300 = £13,500
- Offer B
- 100% up to £100, 25x on bonus only
- B — bonus received
- £100
- B — total stake required
- 25 × £100 = £2,500
Offer A gives twice the bonus and demands more than five times the turnover. At a 4% house edge, A implies roughly £540 of expected loss to clear against B's £100.
Step four: check the ceiling and the clock
Two final terms decide whether the maths above survives contact with reality. The maximum conversion caps what bonus winnings can become withdrawable cash. The expiry period sets how long you have.
An offer requiring £13,500 of turnover inside seven days is asking for roughly £1,900 of stakes a day. If that is not a pace you would play at anyway, the offer is not really available to you regardless of how it is advertised.
A shortcut that works
If you only have a minute: divide the total required turnover by the bonus amount. The lower that ratio, the better the offer, and it collapses match percentage, cap and wagering base into a single comparable figure.
In the example above, Offer A scores 67.5 and Offer B scores 25. Lower is better, and the gap is far wider than the headline numbers suggest.
Common questions
Is a no-deposit bonus better than a matched deposit?
It is free to take, which is genuinely different, but no-deposit offers are usually small and carry high wagering with a low maximum conversion. Treat the conversion cap as the real value: if £10 of free credit can convert to at most £50, that cap is the ceiling on the offer regardless of how well it goes.
Do bigger bonuses mean better casinos?
No. Bonus size is an acquisition cost the operator chooses to pay, and aggressive offers are often paired with heavier wagering. It says nothing about payout speed, support quality or game range.
Should I always take the welcome bonus?
Not automatically. A bonus binds your deposit to a wagering requirement and a set of restrictions. If you intend to deposit, play a little and withdraw, declining the bonus keeps your money free to take out at any time.
What single term should I check first?
What the wagering multiplier applies to. "35x bonus" versus "35x deposit plus bonus" changes the required turnover by more than most differences in the headline percentage.
Read next
This page explains how bonus terms work. It is not advice to gamble, and none of the maths here makes a game profitable — every offer described still carries a house edge. 18+ only. Free, confidential support is at BeGambleAware.org.