Free tool

Bonus Cost Calculator (after gaming tax)

What a casino or sportsbook bonus really costs per player after wagering, completion and gambling tax, and whether it pays back. Compare the same offer in two markets.

Rates last checked 2026-10-20

Market

Compare with

Offer type

The offer

Match

Max bonus

Min deposit

Average deposit

Wagering & play

Wagering

Wagering applies to

Game weighting

Average RTP

Max cashout

Expiry

days

Player economics

Take-up (of FTDs)

Completion rate

Expected GGR per FTD

Over your payback window

CPA / marketing per FTD

Audience

Mixed product (e.g. bet to unlock spins)

Result

After-tax cost per FTD

£6.30

£6,300 per 1,000 FTDs

Cost per claimer

£9.00

gross £9.00

Net contribution per FTD

£83.70

ROI 1329%

Break-even NGR / player

£4.20

£10.50 GGR

How we got there

Offer type: Deposit match
Bonus credited 100% of a £50.00 deposit, capped at £100.00: £50.00
Wagering turnover required 10x bonus: £500.00
House edge recovered while wagering £500.00 x 4.0% edge: £20.00
Cost per player who completes Bonus value minus edge recovered, floored at 0: £30.00
Gross cost per claimer 30% complete; non-completers forfeit the bonus: £9.00
Tax effect of the bonus Not deductible: the bonus does not reduce the 40.0% tax, so the operator bears 100% of it: £0.00
After-tax cost per claimer: £9.00
After-tax cost per FTD 70% of FTDs claim: £6.30
After-tax cost per 1,000 FTDs: £6,300
Tax on the player's own play 40.0% of £150.00 expected GGR per FTD: £60.00
Bonus cost as % of expected GGR: 4.2%
After-tax bonus cost as % of post-tax GGR: 7.0%
Net contribution per FTD Post-tax GGR minus after-tax bonus cost: £83.70
Break-even NGR per player Equivalent to £10.50 GGR per FTD: £4.20

United Kingdom: 40% on GGR, bonus deductible: No. Remote Gaming Duty rose from 21% to 40% on 1 April 2026. Freeplays staked count as nil value, so a bonus never reduces the duty: the operator carries 100% of the bonus cost. Rate last checked: 2026-10-20. Source

Track what your competitors' offers really cost

BonusBench tracks live operator promotions across your markets. Load any of them into this calculator and build offers that pay back after tax.

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An estimate from a simplified expected-value model, not tax or legal advice. Rates change; check them with your tax adviser and regulator before relying on the result.

How it works

The calculator estimates the expected cost of an offer, not its headline. It starts from what a typical player is credited (a 100% match on a £50 deposit is £50, whatever the cap), then subtracts the house edge the operator recovers while that player meets the wagering requirement. Players who do not finish wagering forfeit the bonus, so the cost is weighted by the completion rate, and then by the share of first-time depositors who claim. The tax layer then applies the selected market's rules.

The formula

cost per completer = min(max(0, bonus − wagering turnover ÷ weighting × (1 − RTP)), max cashout)
gross cost per FTD = cost per completer × completion rate × take-up rate
after-tax cost = gross cost × (1 − tax rate × deductible share), or + stakes tax on bonus turnover
net contribution per FTD = GGR × (1 − effective tax rate) − after-tax cost − CPA

Free spins are valued at expected winnings (spins × value × RTP). Free bets are valued with the stake not returned (stake × return × (1 − 1/odds)). Cashback is the percentage of expected net losses, up to its cap.

Worked example

A UK casino offers 100% up to £100 with 10x wagering on the bonus. With a £50 average deposit and 96% RTP slots:

The player is credited £50 and must stake £500. At a 4% house edge, £20 is recovered on average.
A player who completes takes £30. If 30% complete, that is £9.00 per claimer; at 70% take-up, £6.30 per first-time depositor.
UK Remote Gaming Duty is 40% and bonuses are not deductible, so the operator bears the whole £6.30.
With £150 GGR per FTD, the operator keeps £90 after duty and £83.70 after the bonus. The offer pays back once a player reaches £10.50 of GGR.

These are the default inputs: change any of them above and the breakdown shows each step. For the full method, read how to calculate the true cost of a casino bonus.

Frequently asked questions

Is the bonus cost calculator free?

Yes. It runs in your browser, needs no account and stores nothing. The link updates as you type, so you can share a result; it contains only the offer parameters.

Which offer types does it handle?

Deposit matches, free spins, no-deposit bonuses, cashback and sportsbook free bets, with wagering on the bonus or on bonus plus deposit, game weighting, RTP, max cashout and expiry.

Which tax regimes are included?

The UK (40% Remote Gaming Duty from April 2026, 15% remote betting), the Netherlands, Italy, Denmark, Sweden, Spain, Ontario, Malta, Pennsylvania and Germany's stakes-based slot tax, plus a custom rate with a GGR, NGR or stakes base. Each shows the date it was last checked.

How accurate is the result?

It is a deterministic expected-value model, good for comparing offers and markets. The two inputs that matter most, completion rate and GGR per depositor, should come from your own data. It does not model bonus abuse, payment costs or incrementality.

What is break-even NGR per player?

The net gaming revenue (GGR after the bonus) a depositing player must generate for the offer and its tax to pay back. Where bonuses are not tax-deductible, as in the UK, it is above zero.

Guides

Sources

This article explains a cost model. It is not tax, legal or compliance advice; rates and rules change, so check them with your adviser and regulator.

See what your competitors' offers really cost

BonusBench tracks live operator promotions market by market, scores them, and lets you cost and build your own against them.

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