Free betting tools
Work out your ROI, check a price, size a stake and convert odds. No account needed.
-
54% at 1.91+3.1% ROI
ROI calculator
See what your win rate and average odds add up to: ROI per bet, break-even win rate and projected profit.
Open -
-1101.91 decimal
Odds converter
Switch a price between decimal, American and fractional, and see its implied probability and payout.
Open -
3 legs at 1.916.97 combined
Parlay calculator
Add your legs to see the combined odds, payout and break-even rate. It also works for accumulators and multis.
Open -
55% at 2.00+10.0% EV
Expected value calculator
Enter the odds and your win chance to see the EV, your edge and the fair price.
Open -
55% at 2.0010.0% of bankroll
Kelly criterion calculator
Turn the odds, your win chance and your bankroll into a full, half or quarter Kelly stake.
Open
Which tool do you need?
- Use the ROI calculator to check whether your win rate and average odds are profitable over time.
- Use the odds converter when a price is in an unfamiliar format, or to see the win rate it needs to break even.
- Use the parlay calculator before you place a multi-leg bet, to see the payout and how often it has to win.
- Use the expected value calculator to check whether a price is worth taking, given how often you think the bet wins.
- Use the Kelly calculator to see the stake that estimate implies, and how a smaller fraction changes it.
To keep a record of your real results, compare the best bet tracking apps.
FAQ
Are these betting tools free?
Yes. All of them are free to use, and you do not need an account or a download.
Do the tools work on my phone?
Yes. They run in your browser on a phone, tablet or computer.
Do they tell me what to bet on?
No. They do the maths on prices and results you enter. They do not give picks or predict results.
Now track the real numbers.
These tools check one price or one bet at a time. Bet Journal records every bet and shows your ROI by sport, bet type and odds range. Free on iOS and web.