The math, in your hands. Free.
The same calculations serious bettors run, with none of the tips and none of the sign-up. The math of betting does not depend on where you live — it is the same everywhere.
Value detector
Compare the bookmaker's odds with the price you think is fair. If there is value, it tells you how much to stake.
OpenOdds converter
Convert odds between decimal, fractional and American, and read the implied probability behind any price.
OpenSurebet calculator
Check whether odds across different bookmakers lock in a guaranteed profit, and how to split the stake.
OpenDutching calculator
Spread your stake across several selections so you collect the same whichever one wins.
OpenAccumulator calculator
Add your selections and see the combined odds, the return and the margin the accumulator stacks up.
OpenCash out calculator
The fair value of closing a bet early, and how much margin the bookmaker keeps on the offer.
OpenRollover calculator
Analyse a bonus and find out if it is excellent, acceptable, doubtful or a trap.
OpenBankroll tracker
Log your bets and see your real ROI, profit, streak and maximum drawdown.
OpenLoss calculator
How much you've handed the bookmakers at your playing pace. The figure no tipster shows you.
OpenThe blog
The bookmaker margin, why accumulators almost never win, how to read odds. The thinking behind the tools.
OpenLooking for the casino math or the poker tools? They each have their own section in the top menu.