Odds Converter
Convert between American, Decimal, Fractional, and Implied Probability. Click Calculate to update.
Ready
American
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Decimal
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Fractional
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Implied Probability
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Tip: You can fill any one format and hit Calculate to update all others.
What the Converter Does
- Converts between:
- American odds (e.g., -130, +160)
- Decimal odds (e.g., 1.83)
- Fractional odds (e.g., 5/2, 11/10)
- Implied Probability (percentage)
- Works from any single valid input and fills the other three formats.
- Disables browser autocomplete/autocorrect on fields.
- Clipboard copy of the results.
Quick Start (User Guide)
- Enter any one format
- American: type a signed integer (e.g., -120 or +150).
- Decimal: enter a number greater than 1 (e.g., 1.91).
- Fractional: enter numerator/denominator (e.g., 5/2).
- Implied Probability: enter a percentage value (e.g., 54.3).
- Press Calculate
- The tool will detect your valid input (priority: American → Decimal → Fractional → Probability), convert internally to decimal, then populate all four formats.
- Review and Copy
- Results appear in the panel below.
- Click Copy results to place the four values into your clipboard for quick sharing or note-taking.
- Clear if Needed
- Click Clear to reset fields and results.
Input Rules and Tips
- American odds: no decimals; use a leading minus for favorites (e.g., -130) and plus for underdogs (e.g., +160).
- Decimal odds: must be greater than 1.00; includes stake in total return.
- Fractional odds: numerator/denominator, both positive integers; we reduce to simplest terms.
- Implied Probability: 0.01% to 99.99% (exclusive of 0% and 100%).
- Paste-friendly: You can paste a value into any single field, then press Calculate.
How Conversions Work (Reference)
- From American to Decimal:
- If positive: decimal = 1 + A/100
- If negative: decimal = 1 + 100/|A|
- Implied Probability from Decimal: p = 1/decimal
- Fractional from Decimal: fractional = decimal − 1, then reduce to simplest terms (n/d)
- American from Decimal:
- If decimal ≥ 2.0: American = +((decimal − 1) × 100)
- If decimal < 2.0: American = −(100 / (decimal − 1))
- Notes:
- Rounding is conservative (2–4 decimals for decimal odds; probability shows 1–3 decimal places depending on magnitude).
- Conversions assume no bookmaker margin (no vig).
Troubleshooting
- Nothing happens when I click Calculate:
- Make sure at least one field has a valid entry. If not, the status chip will say “Please enter a valid value in any one field.”
- Browser auto-suggest still appears:
- We disable autocomplete, autocapitalize, autocorrect, and spellcheck. If a password manager is injecting suggestions, try disabling it for this page or use your browser’s private mode.
- My fractional odds look different than what I typed:
- The tool reduces fractions to simplest terms (e.g., 10/4 becomes 5/2).
- Rounding differs from my book:
- Books may round differently or include vig; our tool presents fair—vigless—conversions with standard rounding.
Example Walkthroughs
- American to others:
- Input: -120 → Calculate
- Output:
- American: -120
- Decimal: 1.83
- Fractional: 5/6
- Implied Probability: 54.55%
- Decimal to others:
- Input: 2.40 → Calculate
- Output:
- American: +140
- Decimal: 2.40
- Fractional: 7/5
- Implied Probability: 41.67%
FAQ
- Can I type in multiple fields? Yes, but only the first valid field in the priority order (American → Decimal → Fractional → Probability) is used for calculation.
- Does it support plus/minus tax or vig? No. This tool assumes fair odds conversions without bookmaker margin.
- What about massive odds (e.g., +50000)? Inputs are sanity-checked to prevent extreme values from causing errors.
Changelog
- 2025-08: First release (calculate-on-click, theme-safe wrapper, autofill suppressed).
Call to Action
Try the Odds Converter now in Tools and Calculators. If you have feedback or want additional betting tools, drop a comment below or contact us on the Best for Guide contact page.


