Free, no sign-up
Betting tools
Everything runs in your browser
Four calculators, no sign-up, no ads. Each one does the arithmetic in your browser — nothing is sent anywhere.
No-vig calculator
Strip the bookmaker’s margin from a 2-way or 3-way market and read the true probability behind the price.
Betting odds calculator
Stake to return, profit, implied probability, and parlays leg by leg.
Odds converter
Decimal, American, fractional and implied percentage, all four at once.
Implied probability calculator
Turn any price into the percentage it quotes, and see how much of it is fee.
Explainers
How betting odds work
Decimal, American and fractional, what each pays, and the probability behind every price.
Vigorish
The fee built into the odds: what it is, how to work it out, why it varies so much.
How the maths works
The full arithmetic, worked through with real numbers, and the honest limits.
And the thing none of them can do
Every calculator on this page waits for you to type a price in. We publish the finished numbers instead — every football match the sharpest bookmaker prices today, margin already removed, updated through the day.
Free tier covers a fifth of each day’s matches, mixed across major and minor competitions. No card needed.