Market
Odds format
Scales every implied probability by the same proportion.
Total implied probability
104.76%
~4.76% built-in bookmaker margin.
Fair prices use the Multiplicative method.
Side A
+100
2.000 decimal
Fair probability 50.00%
Input: -110 (52.38% implied)
Side B
+100
2.000 decimal
Fair probability 50.00%
Input: -110 (52.38% implied)
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Get the embed codeNo-vig examples for two-way, three-way, and underround markets
These are illustrative inputs, not live prices. Every static result uses the Multiplicative method: divide each implied probability by their sum. The interactive calculator also lets you compare Additive, Power, and Shin removal.
Two-way market
Implied total: 104.76%. Excess over 100%: 4.76 percentage points.
| Outcome | Input odds | Implied probability | No-vig probability | No-vig odds |
|---|---|---|---|---|
| Side A | -110 | 52.38% | 50.00% | +100 |
| Side B | -110 | 52.38% | 50.00% | +100 |
Three-way market with a draw
Implied total: 102.86%. Excess over 100%: 2.86 percentage points.
| Outcome | Input odds | Implied probability | No-vig probability | No-vig odds |
|---|---|---|---|---|
| Home | -150 | 60.00% | 58.33% | -140 |
| Draw | +250 | 28.57% | 27.78% | +260 |
| Away | +600 | 14.29% | 13.89% | +620 |
Two-way market under 100%
Implied total: 95.24%. Shortfall below 100%: 4.76 percentage points.
Normalizing this underround increases each side's probability and shortens its fair odds. These entered prices are illustrative, not a live arbitrage opportunity.
| Outcome | Input odds | Implied probability | No-vig probability | No-vig odds |
|---|---|---|---|---|
| Side A | +110 | 47.62% | 50.00% | +100 |
| Side B | +110 | 47.62% | 50.00% | +100 |
Include every mutually exclusive outcome from the same market and settlement rules. A three-way market includes the draw; omitting it changes the denominator. This proportional method preserves the relative implied probabilities. It does not estimate the true chance of an outcome or guarantee a profitable bet. Displayed percentages are rounded, so their displayed sum can differ from 100%.
Compare four no-vig methods
There is no single neutral way to distribute margin in an uneven market. Switch methods in the calculator and compare the fair prices instead of treating one convention as a measured truth.
Multiplicative
Scales every implied probability by the same proportion.
Additive
Removes the same probability-point margin from every outcome.
Power
Finds one exponent that makes the adjusted market total 100%.
Shin
Estimates favorite-longshot bias through the Shin model.
How to remove vig from a three-way market
A three-way moneyline includes home, draw, and away. Enter all three prices together so the calculator measures the complete market. For example, American odds of -150, +250, and +600 imply 102.86% in total. Multiplicative removal normalizes those outcomes to 58.33%, 27.78%, and 13.89%, with fair prices of -140, +260, and +620.
The same calculation works with decimal inputs. Switch the odds format without changing the underlying market, then compare Multiplicative, Additive, Power, and Shin results.
What this is (and isn't)
This is a documented reference implementation of no-vig normalization — dividing each side's implied probability by the market's overround so the set sums to exactly 100%. It doesn't show live sportsbook lines, link to a sportsbook, or take a stake for real money — every price here is one you type in, computed on your device. If you need live odds data behind this math, that's what the API is for.
Embed the calculator
Add the same four-method calculator to a documentation page or internal tool. It stays client-side and the visible credit points readers back to this reference.
<div data-bbd-calculator>
<iframe src="https://bigballsdata.com/embed/tools/no-vig-calculator" title="Free no-vig calculator" width="100%" height="820" loading="lazy" style="border:0;border-radius:16px"></iframe>
<p style="margin:8px 0 0;font:14px/1.5 system-ui,sans-serif">
<a href="https://bigballsdata.com/tools/no-vig-calculator?utm_source=embed&utm_medium=referral&utm_campaign=calculator_embed" rel="nofollow">No-vig calculator by Big Balls Sports Data</a>
</p>
<script>
(function () {
var root = document.currentScript && document.currentScript.parentElement;
var frame = root && root.querySelector('iframe');
if (!frame) return;
window.addEventListener('message', function (event) {
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frame.height = String(Math.max(320, Math.min(1600, Math.ceil(data.height))));
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</div>Frequently asked
- What is a "no-vig" or "fair odds" calculation?
- Every posted market has a built-in bookmaker margin (the "vig"), which is why implied probabilities across all sides of a market sum to more than 100%. Removing the vig means normalizing each side’s implied probability so the full set sums to exactly 100% — the odds you’d see in a theoretically zero-margin market.
- How is the overround (vig) calculated?
- Convert each side’s American odds to decimal, take the implied probability of each (1 / decimal), and sum them. In a normal market that sum — the overround — is greater than 100%; the amount over 100% is the vig.
- How do you get each side’s fair probability from the overround?
- Multiplicative removal divides each raw implied probability by the overround. The calculator also supports Additive, Power, and Shin methods because each makes a different assumption about how the margin is distributed across outcomes.
- Does this work for a three-way moneyline or 1X2 market?
- Yes. Choose 3-way, then enter the home, draw, and away prices in American or decimal format. All three outcomes are normalized together. Leaving out the draw would produce the wrong overround and fair prices.
- What if the implied probabilities sum to under 100%?
- That’s not invalid input — it just means the odds you entered were already more generous than "fair" (an arbitrage-shaped price). Normalizing up to exactly 100% in that case makes the fair odds worse (lower payout) than the input on every side, the opposite of the normal vig-stripping direction. This calculator handles it without erroring.
- Does this calculator use live sportsbook odds?
- No. It runs entirely in your browser on the numbers you type in — no live odds feed, no vendor data, nothing sent to a server. It’s a reference implementation of the no-vig math, not a betting page.
Need the live odds behind the math?
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