plainodds

Line Shopping Calculator

Compare odds across 2–6 sportsbooks. See the best line, how much you'd leave on the table elsewhere, and the no-vig fair price if you have the opposing side.

Compare books

Odds format (applies to all books)
Books (3)

2 to 6 books. Book name is optional.

If you have the opposite side's odds from any book (ideally a sharp one), entering it here lets the calculator compute the no-vig fair line for your side.

Line shopping, plain

What is line shopping?

Line shopping is comparing the odds on the same bet across multiple sportsbooks and placing the bet at the one offering the best price. The books move their lines independently based on bet flow and risk management — so for any given game, one book usually has a slightly better price than the others.

If DraftKings has the Chiefs at −3 (−110), FanDuel has them at −3 (−105), and BetMGM has them at −2.5 (−115), the bettor who lines up an account at all three books and takes the best available price wins more long-run than the bettor who only uses one book.

How much does line shopping actually save?

The gap between the best and worst price across 4-6 mainstream US books is usually 2-5% on standard markets like NFL spreads. On a $100 bet, that's $2-5 per bet. Across 200 bets a season, line shopping alone adds $400-1,000 in expected profit — even before any handicapping edge.

The effect is bigger in less-efficient markets (player props, futures, college sports) where the spread between books widens. On a player prop you might see best-vs-worst gaps of 10-15%.

What does "no-vig fair line" mean?

The no-vig fair line is what the odds would be if the sportsbook took no commission. To compute it, you need both sides of the market — the side you're betting AND the opposite side. Add the two implied probabilities; the amount they exceed 100% is the book's hold. Divide each side by the total to get its true no-vig probability, then convert back to odds.

If the best book's price for your side is above the no-vig fair line, you've found a positive-EV bet — your expected long-run profit is positive. See how to remove vig from odds for the full walkthrough.

Why isn't this live odds integration?

PlainOdds doesn't pull live sportsbook data — pricing, regulatory, and reliability tradeoffs we've chosen not to make. You enter the odds manually (copy/paste from each book's app or website). The math runs on your input, not on a real-time feed.

If you want live odds across many books, services like OddsJam and OddsPortal aggregate that data (usually behind a paywall). For honest math on the lines you have in front of you right now, this calculator is enough.