Enter both sides
Use the two-way line from a sharp book. For soccer and other 3-way markets, add the draw.
No-vig fair odds calculator
Enter both sides of a market. The calculator removes the book's margin and shows the fair odds, the true win probability for each side, and the hold you pay to bet the line.
Check a price
The odds your book offers on the side above.
Fair market
| Side | With vig | Fair | Fair odds |
|---|---|---|---|
| Side A | 60.00% | 57.98% | -138 / 1.725 |
| Side B | 43.48% | 42.02% | +138 / 2.38 |
| Draw | - | - | - |
Hold3.48%
EV at your price+2.94%
Edge over the fair price+1.20 pts
Positive EV. +145 on Side B beats the fair +138. Expected profit is $2.94 per $100 staked.
Proportional de-vig, the standard method. The fair price is only as sharp as the line you enter, so start from a sharp book.
How it works, the math and FAQ
How to use the calculator
From a posted line to a fair price
Read the fair price
The calculator scales each side's implied probability so the market sums to 100%. The result is the fair win probability for each side.
Shop a better number
Enter the price at your book. A price above the fair price carries positive expected value.
Why de-vig
The vig hides the real price
A book never posts the fair price. The margin sits on both sides of every line, so the implied probabilities add up to more than 100%. Remove the margin and you get the market's own estimate of each side.
Sharp books with low holds and high limits set the most accurate prices. De-vig their line, compare the fair price to the odds at a softer book, and you have a number to bet against. The same math grades your bets after the fact: beat the fair closing price over a large sample and you are beating the market.
The formulas
How the no-vig math works
implied = 1 / decimal odds
hold = implied A + implied B - 1
fair A = implied A / (implied A + implied B)
fair odds A = 1 / fair A
3-way: divide by the sum of all three
Example: -150 / +130
- Implied: 1 / 1.667 = 60.00% and 1 / 2.30 = 43.48%
- Total: 103.48%, so the hold is 3.48%
- Fair: 60.00 / 103.48 = 57.98% and 42.02%
- Fair odds: -138 and +138
Reference
Hold and fair odds on common lines
Two-way markets, de-vigged with the proportional method.
| Posted line | Hold | Fair side A | Fair side B |
|---|---|---|---|
| -105 / -105 | 2.44% | +100 (50.0%) | +100 (50.0%) |
| -110 / -110 | 4.76% | +100 (50.0%) | +100 (50.0%) |
| -115 / -105 | 4.71% | -104 (51.1%) | +104 (48.9%) |
| -120 / +100 | 4.55% | -109 (52.2%) | +109 (47.8%) |
| -130 / +110 | 4.14% | -119 (54.3%) | +119 (45.7%) |
| -150 / +130 | 3.48% | -138 (58.0%) | +138 (42.0%) |
| -200 / +170 | 3.70% | -180 (64.3%) | +180 (35.7%) |
| -250 / +205 | 4.22% | -218 (68.5%) | +218 (31.5%) |
| -300 / +240 | 4.41% | -255 (71.8%) | +255 (28.2%) |
FAQ
Common questions
What are no-vig odds?
No-vig odds are the fair odds left after you remove the sportsbook's margin. A -110/-110 market de-vigs to +100 on both sides, a 50% chance each.
How do you calculate the vig on a bet?
Convert both sides to implied probability, add them, and subtract 100%. -110/-110 gives 52.38% + 52.38% = 104.76%, so the vig is 4.76%.
What is a good hold percentage?
Sharp books run about 2% to 3% on major markets. Standard -110/-110 sides carry 4.76%. Player props and parlays at retail books often run 8% or more.
Which de-vig method does this calculator use?
Proportional, also called multiplicative. The calculator divides each side's implied probability by the market total. Power, Shin and logarithmic methods shift more of the margin onto the longshot. Proportional is the standard starting point.
Where should the input line come from?
Use the sharpest market available to you, such as Pinnacle, Circa or an exchange. A sharp line sets the fair price. Then compare the fair price to the odds at your own book.
The Kennel
Read the math in depth
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