Sports betting calculators.
Seven free, no-signup calculators that run the same math Iron Marker automates: expected value, no-vig fair odds, Kelly staking, odds conversion, hold, parlays, and arbitrage. Correct formulas, instant results, American or decimal odds.
EV Betting Calculator
Compare your odds to the fair line and see the expected value, edge %, and Kelly stake for any wager instantly.
No-Vig / Fair Odds Calculator
Strip the bookmaker's margin out of a 2-way or 3-way market to recover the true, no-vig probability and price.
Kelly Criterion Calculator
Turn your edge and win probability into an optimal stake, with fractional Kelly to keep variance in check.
American Odds Calculator & Converter
Calculate the payout on any American price for your stake, and convert to decimal, fractional, and implied probability — live.
Hold Calculator (Vig / Juice)
Measure a market's overround and hold percentage so you know exactly how much edge the book is charging.
Parlay Calculator
Combine any number of legs into one price and payout — plus an honest look at why parlays stack the vig.
Arbitrage Calculator
Check whether two books lock in a guaranteed profit, and get the exact stake split to secure it.
Embed the EV Calculator
Put the free EV calculator on your own site or blog — one script tag or iframe, no signup, mobile-ready.
+EV Betting Guides
Plain-English explainers on expected value, closing line value, Kelly, and removing the vig — the concepts behind every tool.
Stop doing this by hand.
Iron Marker runs every one of these calculations across thousands of live markets, removes the vig from the sharp line, and surfaces only the bets that are genuinely +EV — with the Kelly stake already set. $39/mo, 7-day free trial.
Start free trialIron Marker is an analytics tool, not a sportsbook, and these calculators are educational — not betting or financial advice. Must be 21+. Problem gambling? Call 1-800-GAMBLER.