Updated Betting & Probability Tool

Odds Converter Calculator

Convert American, decimal and fractional odds, get implied probability, expected value, break-even percentage and Kelly Criterion stake sizing in one betting math calculator.

American, Decimal & Fractional Odds Implied Probability & Break-even Expected Value (EV) per Bet Kelly Criterion Stake Sizing

Interactive Odds Converter, EV & Kelly Calculator

Use the tabs to switch between odds conversion, implied probability, expected value, break-even percentage and Kelly Criterion staking. Enter your odds and your own win probability estimates to see whether a bet is mathematically profitable.

Examples: decimal 2.50, American +150 or -200, fractional 5/2, probability 40 (for 40%).

This mode converts to all three odds formats plus implied probability so you can see every view of the same price.

Implied probability shows what win rate the odds assume before any bookmaker margin or personal edge.

Expected value (EV) uses your own probability estimate to show the average profit or loss per bet over the long run.

Break-even win percentage tells you the minimum hit rate you need so that the bet neither wins nor loses money on average.

Kelly Criterion gives an optimal fraction of bankroll to stake when your estimated edge is positive. Many bettors use fractions such as half-Kelly for more conservative staking.

What Odds Converter Calculator Calculates

Use Odds Converter Calculator to convert American, decimal and fractional odds, get implied probability, expected value.

For more tools in this field, browse Math Calculators.

Odds Converter Calculator Inputs

Odds Converter Calculator uses Input odds type, Input value, Decimal places, Odds type, Odds value.

Odds Converter Calculator Formula or Method

  • d = 1 + n/d.
  • For A > 0 (positive odds): d = 1 + A / 100.
  • For A < 0 (negative odds): d = 1 + 100 / |A|.

Reading Odds Converter Calculator Results

The results include Decimal odds, American odds, Fractional odds, Implied probability, Fair odds if no margin, Implied probability from odds.

Alongside Odds Converter Calculator, use Probability Calculator to work with single events, combined events and conditional probability.

For a different result from Odds Converter Calculator, Binomial Probability Calculator can compute exact binomial probabilities for a given number of trials n, success probability p and number of successes k.

Calculators Related to Odds Converter Calculator

After checking Odds Converter Calculator, use Binomial Distribution Calculator to compute binomial probabilities, cumulative probabilities, tail probabilities and summary statistics. When you need to analyze datasets with arithmetic mean, weighted mean, geometric mean, harmonic mean, trimmed mean, frequency and grouped mean, use Mean Calculator. Normal Distribution Calculator covers a separate task: compute PDF, CDF, Z-scores, tail probabilities and inverse normal values for any normal distribution.

After checking Odds Converter Calculator, use Geometric Distribution Calculator to compute probabilities for the geometric distribution using both definitions: failures before the first success and trial number of the first success. When you need to calculate mean, median, mode, variance, standard deviation, probability, Z-scores, normal distribution, combinations, permutations, correlation, use Statistics Calculator. Population & Sample Population & Sample Variance Calculator covers a separate task: calculate population or sample variance and standard deviation from raw values, grouped data or summary statistics, and compare the spread of two datasets.

After checking Odds Converter Calculator, use Linear Regression Calculator to fit a line of fit to your data, compute slope, intercept, correlation (r) and R².

Frequently Asked Questions About Odds Converter Calculator

It is used to convert American, decimal and fractional odds, get implied probability, expected value.

It uses Input odds type, Input value, Decimal places, Odds type, Odds value.

Odds Converter Calculator uses d = 1 + n/d.

It returns Decimal odds, American odds, Fractional odds, Implied probability, Fair odds if no margin, Implied probability from odds.

Check Input odds type, Input value, Decimal places first. Differences can also come from rounding, unit choices, or a different formula or rule set.