No-vig calculator (fair odds and margin)
Answer: enter the two or three prices of one market and this calculator removes the bookmaker margin proportionally: implied probability 1/price, divided by the sum of implied probabilities, then inverted to a fair price. It is the same multiplicative method PinnFeed uses for the fair, fairProb and margin fields on every Pinnacle market, including on the Free plan. It runs in your browser; nothing is sent to us.
Get a free key to pull these fields for live Pinnacle markets instead of typing prices (no card, REST delayed 30 seconds).
Calculator#
Results are rounded the way the API rounds them: margin and fairProb to 5 decimals, fair to 4. American prices are converted to decimal (4 decimals) before the margin is removed, as the API does.
What no-vig means#
A bookmaker's prices add up to more than 100% implied probability. The excess is the margin (also called overround, vig or juice). "No-vig" or "fair" odds are the prices with that margin removed, so the probabilities of one market sum to exactly 1. They are an estimate of the market's view, used as a reference line for value screens and closing line value. They are not a prediction and not a tip.
The method (multiplicative / proportional)#
For a market with outcomes 1..n and decimal prices d_i:
| Step | Formula | Field on the PinnFeed API |
|---|---|---|
| Implied probability | implied_i = 1 / d_i | — |
| Margin | Σ implied_i − 1 | margin (5 decimals) |
| Fair probability | implied_i / Σ implied_j | fairProb (5 decimals) |
| Fair price | 1 / fairProb_i | fair (4 decimals) |
The same steps work for two-way markets (moneyline without a draw, totals, spreads) and three-way markets (1X2). This proportional method spreads the margin evenly in probability terms. Other methods, such as power or Shin, shift more of the margin onto longshots and give slightly different numbers for big underdogs. This calculator and the API use only the proportional method; we do not claim it is more accurate than other methods or than other data providers.
Worked examples#
These prices are illustrative, not live quotes. The outputs were produced by the same devig() code that computes the API fields.
| Market | Prices | Margin | fairProb | fair |
|---|---|---|---|---|
| Two-way total, American | -105 / -105 (→ 1.9524 / 1.9524) | 0.02438 (2.438%) | 0.5 / 0.5 | 2.0 / 2.0 |
| Two-way moneyline, decimal | 1.80 / 2.10 | 0.03175 (3.175%) | 0.53846 / 0.46154 | 1.8571 / 2.1667 |
| Three-way 1X2, decimal | 2.10 / 3.45 / 3.60 | 0.04382 (4.382%) | 0.4562 / 0.27769 / 0.26612 | 2.192 / 3.6012 / 3.7578 |
Step by step for the 1X2 row: 1/2.10 + 1/3.45 + 1/3.60 = 0.47619 + 0.28986 + 0.27778 = 1.04382, so the margin is 4.382%. Home's fair probability is 0.47619 / 1.04382 = 0.4562 and its fair price 1 / 0.4562 ≈ 2.192. The -105 / -105 row is the same example the schema docs use.
Skip the typing: fair odds from the API#
Every Pinnacle market on PinnFeed already carries these fields, so a bot or sheet does not need to recompute them:
export PINNFEED_KEY="ps_live_..." # your key, never hardcode it in shared code
curl -H "x-api-key: $PINNFEED_KEY" \
"https://pinnfeed.io/v1/odds?sport=soccer&main=true&limit=5"
# each outcome: { "name": "home", "decimal": 2.1, "fair": 2.192, "fairProb": 0.4562 }
# each market: { "margin": 0.04382, ... } (illustrative values)
The Free plan returns fair, fairProb and margin on main markets, delayed 30 seconds. Get a free key, no card needed. If you want each price change pushed as it happens, the WebSocket starts at Builder, €99/mo with 3 WebSocket connections (3-day trial; a card is required and it is charged after day 3 unless you cancel).
For spreadsheet formulas, see the no-vig calculator for Excel and Google Sheets. For what to do with a fair price, see the value-betting guide.
Questions about no-vig odds#
Is this calculator free?#
Yes. It runs in your browser, needs no account and sends nothing to PinnFeed. A free API key is only needed if you want the fields for live markets.
Which no-vig method does it use?#
The multiplicative (proportional) method: each implied probability divided by the sum of implied probabilities. It is the method behind the API's fairProb and fair fields. Power and Shin methods are not offered here.
Does it work for three-way markets?#
Yes. Fill in all three outcomes of a 1X2 market (home, draw, away). Leave the third field empty for a two-way market such as a total or a moneyline without a draw.
Why does my result differ from another no-vig calculator?#
Usually because the other tool uses a different method (power, Shin or additive) or different rounding. The proportional method and API rounding are documented above.
Are fair odds a betting tip?#
No. Fair odds remove the margin from one book's prices; they say nothing certain about the result. This page is educational content for adults (18+). No outcome or profit is guaranteed.
Related reading#
- Get a free key and call
/v1/oddswith the quickstart - No-vig fair odds API: fields and plans
- Value betting with no-vig fair odds
- All free tools
By the PinnFeed team. Educational content for adults (18+). Gamble responsibly. PinnFeed is independent and not affiliated with Pinnacle.