Cashback maths explained

Cashback maths in one formula

Every cashback bonus reduces to a rate applied to a base. The rate is the headline number (5%, 10%, 20%). The base is the part people skip: it might be your net loss over a day or a week, your losses on certain games only, or your total stakes whatever the result. Change the base and the same 10% can be worth £2 or £20.

So the working version of the cashback maths is: value = base × rate − expected cost of any wagering on the cashback. If the money comes back as withdrawable cash, the last part is zero. If it comes back as bonus funds with a playthrough, you subtract the average cost of meeting it, which we work through below.

That third row is why stake-based schemes quote tiny percentages. A rebate on turnover pays out even in winning sessions, so a rate anywhere near the house edge would cost the casino more than it earns. Loss-based offers can quote larger rates because they only pay when you finish down.

Loss-based cashback vs stake-based money back

The two models behave differently over time, and the difference matters more than the headline rate. A lossback bonus returns part of what you lost over a set window. A stake rebate, like rakeback on poker or PlayOJO's OJOplus on casino games, credits a small share of each bet as you go.

In practice, neither kind lowers the house edge to zero. A stake rebate shaves a fixed slice off it; a loss rebate shaves off a slice of whatever losses you actually record. See OJOplus vs cashback for a side-by-side of the two approaches.

Worked cashback maths on a net-loss offer

Take a hypothetical weekly offer: 10% back on net losses, capped at £50, paid as cash with no wagering. Here is how three different weeks play out with the same £100 deposited.

Two lessons fall out of the table. First, the cashback never makes a losing week a winning one; it softens it by the rate. Second, the offer pays most when things go worst, which is exactly why responsible operators and regulators are wary of cashback being used to encourage people to keep playing. We cover that further down.

Why a £100 deposit can mean thousands in stakes

Cashback maths often gets mixed up with deposit size. The base for a loss rebate is what you lose, but your expected loss depends on turnover, not deposit. If you play a 96% RTP slot and keep recycling winnings, £100 can turn over well beyond £100 before it runs out; on average, a 4% edge eats £4 for every £100 staked. That is why the same deposit can produce very different net losses from one week to the next.

How cashback changes the house edge

The house edge is the average share of each stake a game keeps over the long run. Cashback hands a slice of that back, so the useful question is how much of the edge is left after the rebate.

The loss-cashback column is approximate because real sessions don't land on the average. Some weeks finish ahead and earn nothing back, others finish further down. Because winning weeks are never charged anything, the long-run return from a loss rebate is slightly above rate × average loss, but it stays a fraction of the cost. The 0.5% stake rebate is an illustration only, not any casino's published rate: whatever the real figure, the effective edge is roughly the game's edge minus the rebate rate.

These are long-run averages. Any single session can differ widely from them, in either direction. Cashback changes the size of the cost, not the fact that there is one.

Cashback with wagering: the 10x cap in the sums

Some cashback is paid as bonus funds rather than cash. In Great Britain, the Gambling Commission's rewards and bonuses code (LCCP 5.1.1) (opens in a new tab) has capped bonus wagering at 10 times the bonus since 19 January 2026, so the old 30x or 40x cashback playthroughs are gone. A 10x wagering cap still has a price, though.

So £10 of cashback with 10x wagering is worth roughly £6 on average on a 96% slot, before any max bet rule or expiry date is considered. See how cashback is paid for the mechanics of cash versus bonus credits.

Caps, minimum losses and qualifying periods

The rate tells you the most a cashback can be worth per pound; the caps and thresholds tell you where that stops. Three limits appear again and again in cashback terms:

• A cap on the payment (for example £20 or £50 per week). Above it, the effective rate falls with every extra pound lost.
• A minimum net loss before anything is paid (for example £10). Small losing weeks earn nothing.
• A qualifying period: a day, a weekend, a week or a calendar month. Losses in one period don't carry over into the next.

The bottom two rows make an important point: losing more does not buy better cashback value. Past the cap, the rate collapses, and the extra losses are simply losses.

How the terms define a net loss

Most disagreements over cashback come down to the definition of net deposit or net loss. The terms usually work it out as deposits made in the period, minus withdrawals, minus the balance left at the end of the period. Some also exclude losses made with bonus funds, or count only games on a named list.

Check four things in that definition: whether bonus play counts; whether pending withdrawals are subtracted; which games are included (live casino and table games are often treated differently from slots, as our page on game weighting explains); and the exact time zone and cut-off for the period. The Commission's guidance on fair and transparent terms (opens in a new tab) expects those conditions to be clear and readily available, not buried.

How to work out a cashback offer's value step by step

Use these steps on any cashback promotion before you opt in. You need only the terms and a calculator.

1. Find the base: net loss, losses on named games, or stakes.
2. Note the rate, the cap and any minimum loss before payment.
3. Write down the period and the cut-off time.
4. Check how it is paid: cash, bonus funds or free spins, and any wagering multiple (10x at most in Great Britain).
5. Estimate the average cost of your planned play: turnover × house edge.
6. Multiply that average loss by the rate, then apply the cap.
7. Subtract the average cost of any wagering on the cashback (cashback × wagering × house edge).
8. Compare what is left with the cost of the play itself, and decide whether you would make that play anyway.

Step 8 is the one that matters. Cashback maths only makes sense for play you had already budgeted for. If the offer is the reason you would play more, the true cost is the extra play, not the rebate.

Cashback maths myths and the honest answers

• "10% cashback means I can only lose 90%." It means 10% of whatever loss the terms count comes back, up to the cap. You can still lose the whole deposit; you get a tenth of it back.
• "Cashback makes slots profitable over time." The rebate is smaller than the edge, so the long-run average is still a loss. Our page on whether cashback bonuses are worth it runs the numbers.
• "Bigger losses earn better cashback." Caps push the effective rate down as losses grow.
• "Cashback with no wagering is the same as cash in hand." It is cash when credited, but you only receive it after the losses that produced it.
• "A stake rebate is better than a loss rebate." Neither wins by definition: stake rebates are smaller but paid every time; loss rebates are larger but paid only when you are down.

Cashback and chasing losses: the safer gambling angle

Loss-based cashback pays more the worse a session goes, which can make it feel as though the next deposit is partly covered. That feeling is the risk. The Commission requires operators to stop marketing and new bonus take-up for customers showing strong signs of harm, and our page on bonuses and harm indicators explains how that works.

If you notice you are depositing again to reach a cashback threshold, or to recover a loss before the period ends, set a deposit limit or take a time-out. The National Gambling Helpline, run by GamCare (opens in a new tab), is free and open 24 hours a day on 0808 8020 133.

Where cashback maths fits with our partner offers

None of our five partners advertises a cashback welcome offer, so we can't point you to one. The nearest feature is PlayOJO's OJOplus, which PlayOJO describes as money back on every game played, with no wagering; we don't quote its rate here, so check PlayOJO's help pages (opens in a new tab) and the site itself before relying on a figure. Our guide on how OJOplus works covers the mechanics.

The welcome offers are spin-based. 18+, new customers, terms apply. Coral: deposit (some types excluded) and bet £10 on slots to get 100 free spins at 10p (£10 of spins), 48 hours to accept, valid 7 days, no wagering on winnings; runs 1 October 2026 to 1 February 2027; Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards don't qualify. Ladbrokes: spend £10 on slots for 50 free spins a day for 10 days (up to 500 at 10p, so up to £50 of spins), claim each day by 23:59, each batch valid 7 days, no wagering; prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits don't qualify. PlayOJO: 80 free spins on Big Bass Bonanza at 10p (£8 of spins) on a first deposit of £10 or more, no wagering, not available in Northern Ireland.

Those offers sit outside cashback maths because their value is fixed by spins × stake rather than by your losses. Compare them on our free spins page, or return to the casino bonus guides hub for more worked explainers.

18+. Gambling should be entertainment that costs money, not a way to make it. Decide a budget before you play: set a budget. Free, confidential help: National Gambling Helpline 0808 8020 133.