Beginner Guide

How to Read Betting Odds

Master the three odds formats and calculate payouts instantly

American Odds (Moneyline)

American odds are the standard format used by US sportsbooks. They're displayed as positive or negative numbers.

Negative Odds (-)

Meaning: The favorite. The number shows how much you must bet to win $100.

Example: -150
  • Bet $150 to win $100 profit
  • Total return: $250
  • Implied probability: 60%

Formula:
Payout = Stake × (100 / |odds|)

Positive Odds (+)

Meaning: The underdog. The number shows how much you win on a $100 bet.

Example: +200
  • Bet $100 to win $200 profit
  • Total return: $300
  • Implied probability: 33.3%

Formula:
Payout = Stake × (odds / 100)

American Odds Payout Calculator

Decimal Odds

Decimal odds are popular in Europe, Australia, and Canada. They show the total return per $1 wagered (including your stake).

How Decimal Odds Work
Total Return = Stake × Decimal Odds
1.91
$100 bet returns $191
2.50
$100 bet returns $250
4.00
$100 bet returns $400
Why Decimal is Easier

Decimal odds make parlay calculations simple - just multiply all the odds together. Example: 1.91 × 2.50 × 1.50 = 7.16 (a $100 bet returns $716).

Decimal to Implied Probability
Implied Probability = 1 / Decimal Odds × 100

Example: Odds of 2.00 → 1/2.00 = 0.50 = 50% implied probability

Fractional Odds

Fractional odds are the traditional UK format, commonly used in horse racing. They show profit relative to stake.

Reading Fractional Odds

Written as A/B (e.g., 5/2), this means: "For every B dollars wagered, you profit A dollars."

5/2
Bet $2 to profit $5
+250 American
10/11
Bet $11 to profit $10
-110 American
1/1
"Even money"
+100 American
Common Fractional Odds
Fractional American Decimal $100 Profit
1/5-5001.20$20
1/2-2001.50$50
10/11-1101.91$91
1/1 (evens)+1002.00$100
6/5+1202.20$120
3/2+1502.50$150
2/1+2003.00$200
5/1+5006.00$500

Implied Probability

Every odds format can be converted to an implied probability - the likelihood the sportsbook is pricing in for that outcome.

The Vig Creates Overround

When you add up the implied probabilities of all outcomes, they'll exceed 100%. This excess is the sportsbook's profit margin.

Example: Standard -110 on both sides
  • Team A -110 = 52.4% implied
  • Team B -110 = 52.4% implied
  • Total: 104.8% (4.8% overround/vig)
Implied Probability Formulas
Format Formula
American (+) 100 / (odds + 100) × 100
American (-) |odds| / (|odds| + 100) × 100
Decimal 1 / odds × 100
Fractional B / (A + B) × 100

Need to Convert Odds?

Use our full odds converter tool for instant conversions between all formats.

Open Odds Converter
Quick Conversion
AmericanDecimalProb
-5001.2083.3%
-2001.5066.7%
-1501.6760.0%
-1101.9152.4%
+1002.0050.0%
+1502.5040.0%
+2003.0033.3%
+3004.0025.0%
+5006.0016.7%