Back-to-Lay Converter

A Exchange Back bet is similar to a traditional bookmaker bet - you are betting that an outcome will happen.

A Lay bet is the opposite - you are betting that an outcome will not happen. When you place a Lay bet, you are effectively taking the role of the bookmaker and offering odds to another bettor.

For example, in an Over/Under 2.5 Goals market:

• Back Over 2.5 Goals → you win if the match has 3 or more goals.
• Lay Over 2.5 Goals → you win if the match has 0, 1 or 2 goals.

The bettor placing the Back bet and the bettor placing the Lay bet are taking opposite sides of the same market.

When you place a Lay bet, you are offering odds to another bettor who wants to Back that outcome.

The other bettor's Back stake becomes your potential profit. If their bet loses, you keep their stake. However, if their bet wins, you must pay them their profit. This amount is your Lay liability.

For example, if you Lay Over 2.5 Goals at 2.25 Decimal odds, and another bettor places a £10 Back bet:

• If the match has 0, 1 or 2 goals, the Back bettor loses and you win their £10 stake (minus Exchange commission).
• If the match has 3 or more goals, the Back bettor wins and you lose £12.50, which is their profit (£22.50-£10.00) which you must cover. This £12.50 is your liability. Exchange will take its commission from the winner.

Betfair and other Exchanges usually require Lay stake as an input and they derive your liability from it. But as a Lay bettor, you might be more interested in liability than stake, since your level of exposure is defined by your liability. It can help to think of Lay liability as the equivalent of your stake in traditional Back betting terms.

This tool matches Back odds and stakes to Lay odds and liabilities and calculates the equivalent Lay stake that you could input to achieve this liability.

In markets where two opposing outcomes are available, placing a Back bet and Laying the opposite outcome can create the same position.

For example, backing Under 2.5 Goals and laying Over 2.5 Goals both give you exposure to the same outcome: fewer than 3 goals being scored.

• Back Under 2.5 Goals at 1.80 → stake £12.50 to get a £22.50 return, making £10 profit.
• Lay Over 2.5 Goals at 2.25 → accept £12.50 liability (£22.50-£10.00) to potentially win the other bettor's £10 matched stake.

These positions produce the same profit and loss outcome. (Commission does not change the comparison because it is charged on the same profit amount in either case.)

However, Exchange prices are determined by what other bettors are offering, so you may sometimes find a better equivalent price by backing your preferred outcome, while at other times the opposite Lay bet may be more favourable.

This converter helps you compare these equivalent positions.

Back-to-Lay is a trading strategy used by some bettors which is based on the idea of placing both Back and Lay bets with the aim of securing a profit regardless of the outcome of the event.

This strategy capitalises on market developments and price fluctuations.

This converter can be used to calculate and compare Back and Lay positions.

Betfair Exchange uses fixed odds increments, known as odds ticks, rather than allowing every possible decimal price.

For example, 2.00 is followed by 2.02, so there is no 2.01 price available. If the exact mathematical conversion falls between two available ticks, the Exchange Back or Lay figure in this tool is rounded to the next available Betfair Exchange price.

This ensures the price shown is an actual Exchange price you can select rather than a theoretical price that is not available.

Use the commission rate charged by your Exchange account. The default setting in our tool is 2%, but you can change it in Settings if your Exchange charges a different rate.

Commission is usually charged on your net winnings (profit) in a market rather than your stake. The exact rate depends on the Exchange and your account details.

Yes. The conversion logic works with any betting Exchange.

Simply enter in Settings the commission rate charged by your Exchange, and the tool will calculate equivalent prices based on that rate.

Note, however, that the odds increments that this tool considers are based on Betfair Exchange ticks.