Betting calculator
Four tools that run in your browser and send nothing anywhere. The vig remover is the same arithmetic our edges use to find the market's fair price.
Convert a price
Type it any way: -110, +150, 1.91, 5/2 or 40%.
- American
- -110
- Decimal
- 1.909
- Fractional
- 10/11
- Implied probability
- 52.38%
- $100 bet returns
- $190.91
Remove the vig
Both sides of a two-way market. Shows what the book charges and the fair price underneath.
- Book margin
- 3.48%
- Fair probability, A
- 57.98%
- Fair price, A
- -138
- Fair probability, B
- 42.02%
- Fair price, B
- +138
Expected value and stake
Your price and your own probability. Kelly sizes the bet to the edge; most bettors use a fraction of it.
- Break-even probability
- 45.45%
- Your edge
- +4.55 pts
- Expected profit per $100
- $10.00
- Full Kelly
- 8.33% of bankroll
- Stake at 0.25 Kelly
- $20.83
Parlay
Multiply the legs. The cost line estimates how much margin you pay for stacking them, at a typical 4.5% per leg.
- Parlay price
- +811 (9.11)
- Payout
- $91.12
- Profit if it hits
- $81.12
- Implied probability
- 10.98%
- Expected loss to margin, estimated
- 12.4% of stake
Kelly staking assumes your probability is right. If your estimates run hot, full Kelly overbets and burns through a bankroll, so most people bet a quarter of it or less. Parlay legs from the same game are often correlated, and books price that in; the multiplication here treats every leg as independent.