Last Updated on August 22, 2025 by Caesar
What does the Odds Converter free online tool offer? It converts between decimal, fractional and moneyline odds. Include implied probability and potential payout for a stake.
Odds Converter: Decimal ⇄ Fractional ⇄ Moneyline (with Implied Probability & Payout)
Use the odds converter above to switch between decimal, fractional, and moneyline (American) formats. It also calculates implied probability, payout, and profit for any stake—in your chosen currency.
Batch mode lets you paste a list and export CSV.
Why odds formats differ (and why you should care)
- Decimal odds (EU): easiest for payouts—multiply by stake.
- Fractional odds (UK): expresses profit relative to stake (e.g., 5/2 = win 5 for every 2).
- Moneyline odds (US): favorites are negative (−120), underdogs are positive (+150).
If you compare prices across books or build models, you need a fast, accurate converter plus implied probability for apples-to-apples decisions.
Formulas you actually use
Decimal (d)
- Implied probability:
P = 1 / d - Payout:
Payout = Stake × d - Profit:
Profit = Payout − Stake
Fractional (n/d)
- Decimal:
Decimal = 1 + (n / d) - Implied probability:
P = d / (n + d)
Moneyline (ML)
- If ML > 0:
- Decimal:
Decimal = 1 + (ML / 100) - Implied probability:
P = 100 / (ML + 100)
- Decimal:
- If ML < 0:
- Decimal:
Decimal = 1 + (100 / |ML|) - Implied probability:
P = |ML| / (|ML| + 100)
- Decimal:
Quick cheat sheet (copy/paste)
| Input | Decimal | Fractional | Moneyline | Implied Probability |
|---|---|---|---|---|
| 1.80 | 1.80 | 4/5 | -125 | 55.56% |
| 2.00 | 2.00 | 1/1 (Evens) | +100 | 50.00% |
| 2.50 | 2.50 | 3/2 | +150 | 40.00% |
| 3.00 | 3.00 | 2/1 | +200 | 33.33% |
| -120 | 1.83 | 5/6 | -120 | 54.55% |
| +140 | 2.40 | 7/5 | +140 | 41.67% |
(Rounded for readability; the tool outputs exact decimals and clean fractions.)
Example: sanity-check your edge
- Odds: +150 (Decimal 2.50)
- Stake: €100
- Payout: €250
- Profit: €150
- Implied probability: 40%
If your model says true probability is 44%, you have a positive expected value (EV). If it’s 36%, it’s negative EV. Convert, compare, decide.
Batch odds converter: speed for real workflows
Paste a list like:
1.85, 100
5/2 50
-120
+150, 25
evens 40
You’ll get a table with decimal, fractional, moneyline, implied probability, payout, profit, and CSV export. Perfect for line shopping, content prep, or quick QA before publishing picks.
Currency switcher & FX
Set a Base currency for your stake and a Display currency for outputs. Turn on FX to convert payouts (editable rates). Handy when your tip sheet is in GBP but your audience thinks in EUR or USD.
Common pitfalls (avoid them)
- Decimal must be > 1.00 (1.00 would imply 100% chance and zero profit).
- Fractional is profit:stake, not total return.
- Moneyline zeros don’t exist (ML can’t be 0).
- Vig/overround isn’t removed here—these are raw implied probabilities. If you need no-vig probabilities, normalize across both sides.
Glossary (fast definitions)
- Implied probability: the win chance the price suggests.
- Overround/Vig: the bookmaker margin baked into odds.
- Payout:
Stake × Decimal odds. - Profit:
Payout − Stake. - EV (Expected Value): long-run average profit per bet using your true probability.
FAQs
How do I convert fractional to decimal quickly?
Add 1 to the fraction: 5/2 → 1 + 2.5 = 3.5.
What’s the implied probability of −150?
|−150| / (|−150| + 100) = 150 / 250 = 60%.
What’s the implied probability of +200?
100 / (200 + 100) = 33.33%.
How do I calculate payout and profit?
Use decimal: Payout = Stake × Decimal, Profit = Payout − Stake. The converter does both.
Does this tool remove vig?
No. It shows raw implied probability. To de-vig, convert each side to probability and normalize so both sum to 100%.
