CashoutMeter

18+ (19+ in most of Canada, 21+ in most US states). Gambling can be addictive: where to get help. Some links earn us a commission: how that works.

Matched betting calculator

Back at the bookmaker, lay at the exchange, and finish level whatever the result. Enter the offer, the odds and the exchange commission to get your lay stake and what each outcome leaves you with.

Lay stake–
Liability–
Qualifying loss–
Conversion–
OutcomeBookmakerExchangeTotal

18+. A calculator shows what a bet would return, not how likely it is to win. Set a budget before you bet. Free help: GamCare (UK, 0808 8020 133) · Gambling Care (Ireland).

Embed this calculator on your site

Free for tipsters, racing and football blogs, forums and anyone writing about betting. Paste the code into any page that accepts HTML. The script line is optional: it fits the frame to the calculator.

How matched betting works

You back a selection with a bookmaker and lay the same selection at a betting exchange such as Betfair or Smarkets. Laying means taking the other side: you win the backer's stake if the selection loses and pay out if it wins. With the right lay stake, the two bets cancel out.

  1. Qualifying bet. A cash bet that unlocks the offer. Done right it costs a small, known amount.
  2. Free bet. Lay the free bet the same way. The bookmaker's money now does the work, and you lock in most of its value.

The formulas

Qualifying bet: lay stake = back stake × back odds ÷ (lay odds − commission)

Free bet, stake not returned: lay stake = free bet × (back odds − 1) ÷ (lay odds − commission)

Free bet, stake returned: lay stake = free bet × back odds ÷ (lay odds − commission)

Liability is lay stake × (lay odds − 1): the amount the exchange holds from your balance.

Worked examples

Qualifying bet

£10 back at 3.0, lay at 3.1 with 2% commission: lay stake £9.74, liability £20.45. Back bet wins: −£0.45. Lay bet wins: −£0.45. The qualifying loss is £0.45.

Free bet

£10 free bet (stake not returned) backed at 6.0, laid at 6.4 with 2% commission: lay stake £7.84, liability £42.32. Either way you keep about £7.68, a 76.8% conversion. Over both steps the offer leaves £7.23.

Underlay

The same qualifying bet with a lay stake of £8 instead of £9.74: back bet wins £3.20, lay bet wins −£2.16.

What commission costs

CommissionLay stakeQualifying loss
0%£9.68£0.32
2%£9.74£0.45
5%£9.84£0.66

£10 back at 3.0, lay at 3.1. Exchanges charge commission on net winnings in a market; check your exchange's rate.

Questions

What is a qualifying bet in matched betting?

The cash bet a bookmaker asks for before it releases a free bet. You back it at the bookmaker and lay it at an exchange, so you lose only a little whatever happens: £0.45 on £10 at 3.0 laid at 3.1 with 2% commission.

How do I calculate a lay stake?

Qualifying bet: back stake × back odds ÷ (lay odds − commission). Free bet (stake not returned): free bet × (back odds − 1) ÷ (lay odds − commission).

Why are lay odds higher than back odds?

Exchanges show a spread, and the bookmaker builds in its margin. The gap between back and lay odds, plus commission, is what a qualifying bet costs you. Close odds keep the loss small.

What are underlaying and overlaying?

Laying less than the balanced stake (underlay) leaves more profit if the back bet wins; laying more (overlay) leaves more if the lay wins. Both trade a level result for a bet on one side.

Is matched betting legal in the UK?

Yes, it uses bookmaker offers as they are written. Bookmakers can limit accounts that only take offers, and winnings from betting are not taxed in the UK.

More calculators