The percentage belongs to the offer
A contribution rate tells you how much of an eligible stake is credited toward a wagering target. At 100%, a £2 stake counts as £2. At 25%, it counts as 50p. At 0%, it adds nothing. A game can be available to play with cash while excluded from bonus progress.
The Commission’s incentive guidance notes that exclusions within a product category must be clearly stated and accessible in the terms. The existence of a casino-wide bonus does not establish that every game in that casino is eligible.
Use a target and an effective rate
First calculate the qualifying target. A £10 illustrative bonus at 10× has a £100 target. Divide £100 by the contribution rate expressed as a decimal. At 50%, £100 ÷ 0.5 gives £200 of actual eligible stakes. At 10%, the figure is £1,000.
The calculation assumes every stake uses that same rate. If you switch between rates, calculate progress for each group of stakes separately and add the credited amounts. Do not apply an average of the displayed percentages without weighting it by the money staked.
Zero contribution is not a bigger number
When the contribution is zero, there is no finite total of stakes on that game that will complete the target. Division by zero is not a valid answer. Our calculator rejects a zero rate and explains that it cannot produce progress.
Excluded play may also have consequences beyond simply failing to add progress, depending on the terms. Check those consequences before using any restricted funds. Never assume that a visible progress bar authorises an otherwise excluded game.
Keep the game and the rules together
Record the exact title or game identifier, contribution rate, maximum stake and any excluded features. A provider name or a broad category such as slots may not be precise enough to resolve a disagreement later.
A high contribution rate is not a reason to select a game. It gives no guarantee about losses, speed of play or suitability. If an offer becomes confusing, stop and ask for a balance and progress explanation instead of using additional stakes as a test.
Sources & scope
Primary sources checked 9 November 2026. These explain the general framework. An individual offer or dispute depends on its own facts and current terms.
- Gambling Commission: Incentives, practical examples ↗
- Gambling Commission: Rewards and bonuses, SR Code 5.1.1 ↗
Prepared with AI assistance from public sources; no hands-on casino testing is claimed. Read our editorial method.