Free calculators
Run the numbers before you bet.
Four client-side tools for the maths behind the signals — de-vigging, expected value, Kelly staking, and arbitrage stake splits. They work on the prices you type in; no account, no live feed, no promise of profit.
01 · fair odds
De-vig / fair odds
Strip the bookmaker margin out of two- or three-way decimal prices and read the de-vigged fair odds and overround.
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02 · value
Expected value
Compare your probability estimate against a price and see whether the bet has an edge — or a negative expectation.
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03 · staking
Kelly stake
Size a single bet against your bankroll with full or fractional Kelly, and see why the fraction exists.
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04 · windows
Arbitrage stake split
Split a stake across outcomes for an equal return, and check whether the prices are an arbitrage at all before costs.
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PhotonOdds is a sports-betting data & analytics service — not a bookmaker. We never accept wagers or guarantee profit.
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