Wagering Maths: Estimating What a Bonus Is Really Worth
A headline such as a 200% match says little on its own about whether an offer is favourable. What matters is the bonus amount, the wagering requirement, the sum that wagering applies to, the average house edge of eligible games, game-contribution rules, time limits and any maximum-withdrawal cap.
Two simplified formulas give a rough long-run picture. They are educational estimates only. They do not predict any player's outcome and they do not guarantee a profit.
Estimated theoretical loss = required wagering × house edge
Approximate bonus edge = bonus amount − estimated theoretical loss
The first line estimates the average amount the house edge would take over the full wagering requirement in the long run. The second line only holds up where wagering is on the bonus alone and no other restrictive terms materially change the result.
Example A: Short Wagering on a High-RTP Game
A player deposits £50 and receives a £50 bonus. Wagering applies to the bonus only, at 20x, so required wagering is £50 × 20 = £1,000. The eligible game has an average RTP of 98%, giving a house edge of 100% − 98% = 2%. Estimated theoretical loss is £1,000 × 2% = £20, and the approximate bonus edge is £50 − £20 = £30 under these simplified assumptions.
Example B: A Smaller Bonus Close to Break-Even
Here the deposit is £80 and the bonus is £40, with wagering on the bonus only at 35x. Required wagering comes to £40 × 35 = £1,400. With an average RTP of 97%, the house edge is 3%, so the estimated theoretical loss is £1,400 × 3% = £42. The approximate bonus edge is £40 − £42 = −£2, which is effectively break-even on paper.
Example C: Wagering Applied to Deposit Plus Bonus
A £100 deposit earns a £100 bonus, but the 40x requirement applies to deposit plus bonus. The wagering base is £200, so required wagering is £200 × 40 = £8,000. At an average RTP of 96%, the house edge is 4% and the estimated theoretical loss is £8,000 × 4% = £320. The approximate bonus edge is £100 − £320 = −£220. Because wagering includes the deposit, this is an even rougher estimate than the bonus-only cases.
This model loses accuracy when games contribute less than 100% towards wagering, when RTP varies between eligible titles, when a maximum cashout limits winnings, when wagering covers deposit plus bonus, or when the time limit expires before wagering is complete. If a bonus or balance is held in a volatile crypto asset, its GBP value can shift between crediting, wagering and withdrawal; stablecoins reduce price movement but the promotion terms still need reading. RTP is a long-run statistical average, and short sessions can produce very different results.