The free ValueBets.uk betting calculators do the sums behind a price for you. Each one takes a few numbers and shows what the odds really mean, so you can judge a bet before you place it, or decide to leave it.
They are tools for judging prices. None of them can tell you who will win, and no calculator turns betting into a reliable way to make money.
Every calculator in one place
- Odds converter: switch between decimal, fractional and American odds and see the implied percentage.
- Fair odds calculator: enter two or three prices to see the book percentage, the margin and the fair odds.
- Expected value calculator: your stake, the odds and your chance give the EV, the implied chance and your fair odds.
- Kelly calculator: size a stake from the odds, your chance, your bankroll and a Kelly fraction.
- Betting variance calculator: simulates 40 bettors to show how far luck can swing results.
- Free bet calculator: the value of a free bet, and of the whole offer once the qualifying bet is included.
- CLV calculator: compares the odds you took with the closing odds, such as 2.15 against 1.95.
- Betting ROI calculator: profit, yield, ROI on bankroll and average stake from your own record.
- Drip feed calculator: checks in-play goals bets added while a match is still 0-0.
Horse racing calculators
- Each-way calculator: returns if your horse wins, places or finishes outside the places, with place terms and Rule 4.
- Best odds guaranteed calculator: your price against the SP, and what BOG adds.
- Each-way value calculator: checks a bookmaker’s each-way price against exchange win and place prices.
- Extra place calculator: lay stakes and profit for every finishing position when a bookmaker pays extra places.
Which one to use
Start with your question. If you want to know what a price means, use the odds converter. If you want to know whether a price is too short, move on to the fair odds and EV calculators.
Every tool explains its inputs on the page, so there is no guesswork, and each one links to a full guide, such as our value betting guide (Lesson 1 out of 25 in the Masterclass), that explains the maths step by step.
Three calculators, one worked example
Worked example
Brentford are 2.75 to beat Fulham (prices for illustration only). The odds converter shows an implied chance of 1 ÷ 2.75 = 36.4%.
You rate their chance at 40%, so the EV calculator gives 0.40 × 2.75 − 1 = +£0.10 per £1 staked, or +£1.00 on a £10 stake, and your fair odds are 1 ÷ 0.40 = 2.50.
The variance calculator then shows how widely results can swing over hundreds of bets, even with a genuine edge like this one.
Reading the results
A calculator is only as good as the numbers you put into it. If your 40% is really 35%, the same bet has negative EV. Treat every result as an estimate, and remember that any single bet may not land, whatever the maths says.
Our Value Predictor gives picks from a form rule, not guarantees, and in the same way these calculators help you check a price rather than decide to bet.
Related guides
- Implied probability explained (Lesson 2 out of 25 in the Masterclass)
- Expected value betting (Lesson 4 out of 25 in the Masterclass)
- Bankroll management (Lesson 11 out of 25 in the Masterclass)
For independent guidance on gambling in the UK, see the Gambling Commission’s advice for the public.
18+ only. Betting should stay fun. Set a budget before you start, only bet what you can comfortably afford, and take a break whenever you need one. For free, confidential support, visit BeGambleAware.org or call the National Gambling Helpline on 0808 8020 133.