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How to Convert American Odds to Decimal and Fractional
Learn a quick method to convert American odds to decimal and fractional formats with examples you can verify in seconds.
1 min read
American odds can look confusing at first, but conversion is simple once you separate plus odds and minus odds.
Formula for Positive American Odds#
Use this formula:
- Decimal = (American / 100) + 1
Example for +150:
- Decimal = (150 / 100) + 1 = 2.50
Formula for Negative American Odds#
Use this formula:
- Decimal = (100 / |American|) + 1
Example for -110:
- Decimal = (100 / 110) + 1 = 1.909
Convert Decimal to Fractional#
After you have decimal odds:
- Fractional = Decimal - 1
Example for 2.50 decimal:
- Fractional = 1.50 = 3/2
Quick Workflow Before Betting#
- Convert odds to decimal.
- Compute implied probability and compare with your estimate.
- Verify payout using your stake.
Use the live Odds Converter to check your math instantly.
Common Questions
How do you convert +150 to decimal odds?
Divide by 100 and add 1. For +150: 150 / 100 + 1 = 2.50 decimal odds.
How do you convert -110 to decimal odds?
Use 100 / absolute American odds + 1. For -110: 100 / 110 + 1 = 1.909.