About

American sportsbook prices are quoted in a format that makes the payout easy to read and the cost hard to see. −110 does not look like a fee. A six-leg parlay at +4741 does not look like a 24% charge. “$1,000 in bonus bets” is not $1,000. Every tool here exists to put the second number next to the first.

The site publishes its formulas and keeps its opinions out of it. Every calculation is arithmetic you can check by hand, the assumptions behind each one are printed alongside it, and the methodology page carries the lot in one place.

The scope

Everything here is arithmetic on numbers you supply. A price goes in, a payout and a cost come out, and the formula sits beside the result. The tools cover conversion, market margin, parlays, teasers, round robins, hedging, expected value, bonus bet valuation, bankroll survival and tax.

The one editorial judgement on the site is the order of the sportsbook rankings, and that is produced by a published formula applied identically to every entry; opinion does not enter it. Where a figure rests on an assumption, the assumption is printed next to it; where a figure cannot be derived honestly, the page says so instead of supplying one.

Who writes it

The site is written and maintained editorially, without bylines. There is no invented expert here and no stock-photo tipster, because the credibility of a calculator comes from its published formulas rather than from a portrait beside them. Where a figure rests on an assumption, the assumption is named.

Links to sportsbooks are commercial and disclosed as such. See the affiliate disclosure for the short version and the methodology page for what it means for the rankings.

How a figure is checked

Each formula on the site is covered by worked cases with the answer computed by hand first, so a change to the arithmetic has to reproduce every one of them before it ships. The numbers printed as defaults on a calculator page are produced by the same code that answers when you press the button, which means a page cannot quietly drift away from its own result. Intermediate values are carried at full precision and only the display is rounded.

Where two figures could both be called the answer, both are shown and named. A market has an overround and a hold, a bonus bet has a face value and a cash equivalent, and a parlay has an offered price and a fair one. Printing one of each pair without the other is the habit this site was built to break.

Keeping the offers current

The sportsbooks page states the date its advertised figures were read, and every row links to the operator’s own terms, which is where the current condition of an offer lives. Welcome offers change frequently and differ by state, so the ranking describes the offers as they stood on that date and makes no promise about today. When a figure changes the order is recalculated by the same conversion, not adjusted by hand.

Corrections are welcome. The address on the privacy page reaches the site, and a figure that cannot be reproduced from the formula beside it is worth reporting.