Calculators

Enter the odds for each leg and your stake. See the combined price, what it pays and your profit — one leg for a straight bet, more for a parlay.

Give it your edge and it gives you a stake — full, half and quarter Kelly side by side. When the edge isn't there, it says no bet rather than a small one.

Enter a fair price and the price you're offered. It returns the edge as a percentage and per $100, with both implied probabilities — and says plainly when a bet is a bad one.

Two prices on opposite sides at two books. It splits the stake so the return is identical either way, shows the margin, and tells you when there isn't one — which is most of the time.

American, decimal, fractional and implied probability, live as you type — plus both sides of a market at once, for the book's hold and the de-vigged fair price underneath it.

The stake that guarantees the same return either way — and what a free bet is really worth once you convert it to cash. Longer odds convert better; it shows you how much better.