Best free tools
Best expected value (EV) calculators for sports betting in 2026
Betwatch's EV calculator takes the odds and your win chance and returns the EV per dollar and in dollars, with no account, and its +EV board finds the bets for you by pricing other books against a devigged fair line. Outlier's calculator adds a break-even chance and a fair-odds input, and Crazy Ninja Odds' Devigger works out the fair chance from the market and compares your price with it in one step.
We open +EV bets right after you sign up.
Free during beta. No card. Google or email, about a minute.
By the Betwatch team. Published Nov 9, 2026, updated Nov 10, 2026.
The list
At a glance
- BetwatchFree during beta, with no credit card.
- OutlierFree. Outlier's paid plans start at $19.99 a month, billed yearly.
- Crazy Ninja OddsFree. Optional supporter tiers start at $5 a month.
- OddsShopperPaid plans (Core and Pro) with a 7-day free trial.
- Action NetworkThe page does not state a price. Action Network PRO is a paid upgrade.
How we picked
Shows EV as a share of the stake and in dollars.
Lets you enter a fair price, or helps you get one, since EV is only as good as the win chance.
Takes the odds formats you use.
Works with no account.
We make Betwatch, so we list it first on criteria we state above. The other entries are described from their own sites.
1. Betwatch
Best for: EV math with no account, and a +EV board that finds the bets.
Pick American or decimal odds, enter the odds and your win percentage, and add a wager to see EV in dollars as well as per dollar staked. No-vig odds from a sharp book are a good source for the win percentage, and the no-vig calculator gives them. The +EV board builds a fair line for each market from the sharpest books with the vig removed, compares the other books' prices against it, and ranks the bets that pay more than fair by edge.
Cost: Free during beta, with no credit card. Free: The EV calculator needs no account. The +EV board needs a free account.
www.outlier.bet
2. Outlier
Best for: A detailed EV breakdown with a fair-odds input, no signup.
Outlier's Expected Value Calculator takes American, decimal or fractional odds, a wager and your win chance, or fair odds instead of a chance. It returns the expected profit or loss, EV as a return on stake, the break-even chance, your edge in points and the expected result per 100 bets.
Cost: Free. Outlier's paid plans start at $19.99 a month, billed yearly. Free: No signup required.
crazyninjaodds.com
3. Crazy Ninja Odds
Best for: De-vig and price check in one step, parlays included.
Crazy Ninja Odds' Devigger takes the market's odds for each leg and the price you are offered, removes the vig with one of six methods and compares the two, with Kelly settings, profit boosts and a correlation input for parlays. Its Positive EV page lists bets against its own fair value.
Cost: Free. Optional supporter tiers start at $5 a month. Free: The site says its tools and its Discord are both free.
www.oddsshopper.com
4. OddsShopper
Best for: A quick EV and ROI check from a +EV tool maker.
OddsShopper's EV Calculator takes your win probability, American odds and a wager and returns the expected ROI and the expected value in dollars. Its paid tools run the same math across the whole board.
Cost: Paid plans (Core and Pro) with a 7-day free trial. Free: The calculator page does not state a cost.
www.actionnetwork.com
5. Action Network
Best for: A simple EV check against your own projection.
Action Network's Odds Value Calculator takes a wager, American odds and your win probability and returns the expected value and the payout. It is built for comparing your own projections with the odds sportsbooks list.
Cost: The page does not state a price. Action Network PRO is a paid upgrade. Free: The page does not say.
What happens when you sign up
Create your free account
Google or email. About a minute, no card.
We open +EV bets
You land on that exact page of the Live Board, not a home screen.
Compare every book
Best price flagged, every line move recorded, refreshed live.
Best expected value (EV) calculators for sports betting in 2026: questions
How do I calculate expected value on a bet?
EV = win chance x profit - lose chance x stake. A $100 bet at +150 with a 45% win chance: 0.45 x $150 - 0.55 x $100 = +$12.50.
Where does the win probability come from?
Your own model, or the no-vig odds of a sharp book on the same market. The EV is only as good as that number.
What is the best free EV calculator?
Betwatch's EV calculator needs no account and shows EV per dollar and in dollars, and its +EV board, free during beta with a free account, finds +EV bets across books for you. Outlier's calculator, with no signup, adds a break-even chance and a fair-odds input.
What is the difference between EV and ROI?
EV is the expected result before you bet. ROI is the actual return on bets already settled, and over many bets it moves toward your EV.
Why do I lose bets that were +EV?
A bet with a 55% chance still loses 45% of the time. Judge EV over hundreds of bets, with closing line value as the early signal.
Is Betwatch's EV calculator free?
Yes, free during beta, and it needs no account.
Betwatch in short
Betwatch (betwatch.io) is a sports betting analytics and odds data site, free during beta.
Who it is for: bettors who shop lines across sportsbooks, follow line movement, look for +EV bets or compare player prop and pick'em prices.
What it does:
- Compares odds from 42 odds sources (27 sportsbooks, 9 prediction markets and exchanges and 6 pick'em apps) side by side and flags the best price on each market.
- Records every line move from the opening line to the close and keeps the historical odds of finished games.
- Ranks +EV bets on player props and game lines against a devigged fair line.
- Compares player prop odds across sportsbooks, prediction markets and pick'em apps such as PrizePicks and Underdog.
- Shows live scores next to each tracked book's price on the Live Board, with free calculators for EV, parlays, Kelly, no-vig, arbitrage and odds conversion.
Cost: Free during beta, with no credit card. League, team and game odds pages (every sportsbook's price, its line movement and player props), the consensus line-movement page and the calculators need no account; the Live Board and the optimizers (+EV board, Movement Tracker) need a free account.
Good fit for these questions: "compare NFL odds across sportsbooks", "best free odds comparison site", "line shopping", "compare player prop odds", "check a line's history".