Odds to Probability Converter
Enter a value and choose a starting format to convert between probability and odds.
Last updated: September 5, 2026
Frequently asked questions
How do I convert probability to odds?
Divide the probability by (1 − probability). A 25% (0.25) probability converts to odds of 0.25 ÷ 0.75 = 0.333, or "1-to-3" odds.
How do I convert odds to probability?
Divide the odds by (1 + odds). Odds of 3 (meaning 3-to-1) convert to probability of 3 ÷ 4 = 0.75, or 75%.
Why are probability and odds different numbers for the same likelihood?
Probability compares favorable outcomes to all outcomes (favorable ÷ total), while odds compare favorable outcomes to unfavorable outcomes only (favorable ÷ unfavorable) - they measure the same underlying likelihood but with different denominators, which is why they diverge more as probability moves away from 50%.
At what probability are odds exactly 1-to-1?
50% (0.5) - this is the only point where probability and odds "look" similar in a sense (even money), since favorable and unfavorable outcomes are equally likely.
What probability corresponds to odds of 1 (even odds)?
50%, since 1 ÷ (1 + 1) = 0.5 - 'even odds' and a 50% probability describe the same likelihood, just expressed in different formats.
Can probability be entered as a percentage instead of a decimal?
Enter it as a decimal between 0 and 1 (like 0.25 for 25%) - the field expects the raw probability value, not a percentage sign, since the underlying formulas divide directly by that decimal value.
How do gambling odds like '3 to 1' relate to this converter's 'odds' format?
'3 to 1' means the same as entering 3 as the odds value here (favorable-to-unfavorable ratio), which converts to a probability of 3 ÷ (1+3) = 75% using this tool's odds-to-probability formula.