Free betting calculators

Odds and prices

Convert a price, strip out the vig, and see what a worse price costs and what half a point is worth.

Odds converter: −110 gives 52.4% · 1.91 decimal · 10/11 · wins $90.91 on $100. Turn any price into decimal, fractional and the win rate it implies, and back again.No-vig calculator: −110 / −110 gives +100 / +100 · the 4.76% the book keeps, taken off both sides. Take the book’s cut off a two-way line to see what each side is really worth.Worst line vs best line: −115 vs −105 gives $4.24 a bet · on $100 a bet · about $2,120 over 500 bets. What the worse of two prices on the same bet costs you, per bet and over a season.Half point calculator: −3 to −2.5 gives −130 or better · NFL, −110 / −110 · worth it at −125. What half a point onto or off a key number is worth paying, and two spreads compared.

Edges

Is a bet worth taking, how do you split a stake across two books, and is a teaser worth its price?

EV calculator: +110 at 50% gives +$5.00 a bet · +5.0% on $100 · break-even 47.6%. Is a price paying more than the bet is worth? The expected value in dollars and percent.Arbitrage calculator: +110 / +105 gives $494 + $506 · $1,000 split so either result returns $1,037: +$37. Split a stake across two books so either result pays the same.Teaser calculator: +2.5 / +1.5 gives −112 or better · cautious EV · 6-point NFL Wong teaser at −120: −$1.58 per $100. Price an NFL teaser leg by leg: the chance at the teased number and the price it needs.

Stakes and payouts

How much to bet, what a parlay pays, and how to hedge a bet you already hold.

Kelly criterion calculator: +100 at 55% gives $25.00 stake · quarter Kelly on $1,000 · full Kelly is 10% of the bankroll. A stake sized to your edge and your bankroll: full, half or quarter Kelly.Parlay calculator: −110 / −110 / +150 gives +811 · $10 pays $91.12 · all three legs land 11.0% of the time. The combined price, payout and win chance of up to 12 legs.Hedge calculator: $100 at +300, hedge −150 gives $240 for +$60 · the same +$60 whichever side wins. The stake on the other side that gives the same result either way on a bet you hold.

Skip the typing

Every board already shows the best value on each side, sometimes on a better number, and a live no-vig price, and the edges pages list the +EV bets, arbitrage, middles and NFL Wong teasers on the board right now.

+EV betsArbitrageMiddlesWong teasers

Learn the math

New to odds? The learn page starts with how to read American odds and builds up to no-vig prices and +EV, one short guide at a time.

Start learning

Injury news

Key players ruled out, doubtful or back for the games on the board, newest first, with the source and what the line did since.

Open injury news

Frequently asked questions

Are the calculators free?

Yes. Every calculator here is free, and the math runs in your browser with the same code as the live boards.

Do they use the same math as the live boards?

Yes. The no-vig, EV and arbitrage calculators run the same code that builds the no-vig price and finds the edges on the boards, so a result here matches what the site shows for the same prices.

Which calculator should I start with?

The odds converter if you want to read a price, the no-vig calculator if you want to know what a line is really worth, and the EV calculator to judge whether a bet beats it.

Are the numbers on the cards live prices?

No. Each card shows one worked example with inputs we chose, run through that calculator, so you can see what it does before you open it. The live prices are on the boards.

Where do I learn what the numbers mean?

Each calculator page explains its own math and links the guide behind it. The learn page has every guide, starting with a five-step path for beginners.

21+ | Gambling problem? Call 1-800-GAMBLER. Nothing here is betting advice, and no bet or strategy guarantees a profit. Sports betting is legal only in some US states; check the rules where you are. Responsible gambling.