HERMES TOOLS · Do the math yourself
Sports data &Calculators
Understand results, team performance and odds through numbers. Free, works on mobile, and every calculation runs in your browser.
Sports data
Poisson score probability calculator
Enter expected goals to see win / draw / loss odds, a scoreline heat map and both-teams-to-score probability, or load finished-match data from this site.
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Pythagorean expectation calculator
Estimate expected win percentage, wins and the gap to the actual record from MLB / NBA runs or points.
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Magic number / elimination number calculator
Work out how many leader wins plus chaser losses are still needed, and what tonight's results would do.
Open tool ›Odds math
Parlay calculator
Decimal odds and stake for 2–12 legs, with system bets and per-leg win / loss / void.
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Odds format converter
Instant conversion between decimal, Hong Kong, American (moneyline), fractional odds and implied probability, plus margin and fair probability for two- and three-way markets.
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Implied probability & margin calculator
Implied probability, overround, payout rate and margin-free fair probability for a full market.
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Stake sizing & Kelly criterion calculator
Fixed amount, percentage of bankroll, full / half / quarter Kelly and expected value.
Open tool ›2026 World Cup
2026 World Cup predictor
Use the 2026 World Cup's 48-team field and format to rank the groups, pick the best third-placed sides, play through to a champion and create a share image.
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2026 World Cup simulator
Simulate the 2026 World Cup with pre-tournament Elo ratings, adjust team form and match-to-match variance, and run one tournament or 5000 for statistics.
Open tool ›Which tool should I start with?
For football scoreline distributions, start with the Poisson tool. To compare a team's runs or points with its record, use Pythagorean expectation. Late in the season, the magic number tool shows the lead over a single chaser.
Odds tools only convert what you enter. For example, a parlay of 1.80 and 1.90 with 100 units per combination has total odds of 3.42, returns 342 units if every leg wins and makes 242 units profit. Two sides at 1.90 add up to 105.26% implied probability, which is not the real chance of either result.
To replay the 2026 World Cup, use the predictor to rank each group, pick the 8 best third-placed teams and choose your way to a champion, or use the simulator to adjust team form and see different outcomes. Both use pre-tournament data and never update with live or actual results.
FAQ
Do I need to sign up or pay?
No. Every tool works right away and runs in your browser.
How are data tools different from odds tools?
Data tools use runs, points or expected goals. Odds tools only work with the numbers you enter; they offer no betting services or bookmaker recommendations.
Can I share a result?
The seven calculators give you a share URL with your inputs. The World Cup predictor shares text and images, and the simulator can be rerun as often as you like.
This tool is for math and data reference only and offers no betting services. Do not buy sports lottery tickets if you are under 18. Model output does not guarantee real results.