What your parlay actually pays.
Real implied probability per leg. Real combined probability. Real book edge in percent. No book math. No vig hiding. Free.
How this works
Every set of odds carries an implied probability — what the book is pricing the outcome at. For a parlay, your book's combined probability is the product of each leg's implied probability.
The catch: each leg is already overpriced by the book's vig. A -110/-110 market prices both sides at 52.4% implied probability — totaling 104.8%, not 100%. That 4.8% is the book's juice.
Multiply that juice across N legs and you get compounding edge against you. A 4-leg parlay at -110 per leg gives the book ~17–20% edge. A 6-leg parlay gives them ~25–30%.
This calculator de-vigs each leg (dividing by 1.0476 — the typical -110 vig factor) to estimate the true probability, then shows you the book's edge in plain percent. Use it to sanity-check the parlays your friends keep posting.