QuickFreeTools

Online Odds Calculator

Convert between odds formats and implied probability. American, decimal, fractional.

Frequently Asked Questions

What odds formats are supported?
American (+/-), decimal (e.g. 2.50), and fractional (e.g. 3/2). Enter one to get the others and implied probability.
How is implied probability calculated?
For decimal odds: probability = 1/decimal. For American: negative odds → |odds|/(|odds|+100); positive → 100/(odds+100).
What are American odds?
Negative (e.g. -200) means bet that much to win 100; positive (e.g. +150) means bet 100 to win that much.

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