Money back as free bet / bonus lock-in calculator

How to use this calculator:

1. Enter the details of your qualifying bet in the first section.

2. If the bookmaker refunds your losing bet as a free bet, enter the value of that refund in the second section.

3. The calculator will show your qualifying loss, your free bet lock-in profit, and your total guaranteed outcome if the qualifying bet loses.

Example:
If your qualifying back stake is £10, but the bookmaker only refunds £5 as a free bet, then:

• Enter £10 as the qualifying back stake
• Enter £5 as the refund / free bet amount

This is how you calculate the real guaranteed profit from a partial refund offer.

1) Qualifying bet

The amount you place at the bookmaker.
The odds at the bookmaker.
The lay odds at the exchange.
For example, 2 for Smarkets or 5 for Betfair standard.
Lay stake to place for the qualifying bet
£0.00
This is the lay stake to enter on the exchange.
Lay liability for the qualifying bet
£0.00
Make sure you have enough exchange balance to cover this.
Result if the qualifying back bet wins
£0.00
Usually a small qualifying loss or close to break-even.
Result if the qualifying back bet loses
£0.00
This is the result before using the free bet/refund.

2) Refund / free bet

Enter the actual refund amount. This can be lower than your original stake.
The odds you plan to use for the free bet at the bookmaker.
The matching lay odds at the exchange.
Lay stake to place for the free bet
£0.00
This is the exchange lay stake for the refunded free bet.
Lay liability for the free bet
£0.00
The amount needed at the exchange to cover the free bet lay.
Guaranteed profit from the free bet alone
£0.00
Assumes a standard stake-not-returned free bet.
Total result if qualifying bet loses and the refund is matched
£0.00
This is your true lock-in result for the refund scenario.

3) Final outcome summary

Scenario A: qualifying bet wins
£0.00
No refund/free bet is triggered.
Scenario B: qualifying bet loses and refund/free bet is received
£0.00
This includes the qualifying result plus the free bet lock-in.
This calculator assumes the refund is given as a stake-not-returned free bet, which is the most common matched betting setup. If your bookmaker refunds as cash, bonus cash, or stake-returned free bet, the formula would need to be adjusted.