Free Football Betting Calculators

Arbitrage · Value Bet (+EV) · Kelly Criterion · No-Vig Fair Odds. Built for football bettors. No signup, no ads, instant results.

Arbitrage Calculator

Calculate guaranteed profit stakes for 2-way and 3-way (1X2) football arbs.

How to use it

1. Enter the decimal odds for Outcome 1 and Outcome 2 (and Outcome 3 for 1X2 football markets).
2. Enter your total stake — the combined amount you want to bet across all outcomes.
3. The calculator shows the stake for each outcome, guaranteed return, profit, and ROI.
4. If the "Arb %" is below 100%, you have a valid arbitrage opportunity. If it is above 100%, there is no arb.

Formula explained

An arbitrage calculation requires the sum of inverse decimal odds across all outcomes to be less than 1 — any value below 1 represents guaranteed profit before commissions.

Example: Odds 2.10 / 3.60 / 4.20 on a 1X2 market. Arb % = (1/2.10 + 1/3.60 + 1/4.20) × 100 = (0.476 + 0.278 + 0.238) × 100 = 99.2%. Below 100% — valid arb with 0.8% margin.

2-way vs 3-way calculations

A 2-way arb covers two outcomes (Asian handicap, over/under, BTTS). A 3-way arb covers Home Win, Draw, Away Win — football's unique 1X2 structure. 3-way arbs require three bookmaker accounts and three simultaneous bets. Leave Outcome 3 blank for 2-way markets. Football generates more 3-way arbs than any other sport because the Draw creates a third independent pricing decision.

Common mistakes:

• Placing one leg before confirming all odds are still live — odds can move in seconds
• Using odds that include a bookmaker's enhanced promotion — these are often voided
• Ignoring exchange commission (Betfair charges 2–5%) — factor this into your arb % threshold
• Rounding stakes to the nearest £1 without recalculating — small rounding errors eliminate the margin

Value Bet (+EV) Calculator

Calculate edge %, expected value, and Kelly stake for positive EV football bets.

How to use it

1. Enter the bookmaker's decimal odds for the bet you are considering.
2. Enter the fair/sharp odds — use Pinnacle's odds, or use the No-Vig Calculator below to derive them from any market.
3. Enter your stake and bankroll (optional — needed for Kelly stake calculation).
4. The calculator shows edge %, expected value in currency, and recommended Kelly stake.

Edge formula

Edge measures how much better your odds are compared to the fair odds. A positive edge means the bet has positive expected value.

Example: Bookmaker offers 2.40 on Arsenal. Pinnacle prices Arsenal at 2.10 (fair odds). Edge = (2.40/2.10 − 1) × 100 = +14.3%. On a £50 stake, EV = £50 × 0.143 = £7.14 expected profit per bet.

When to bet — and when not to:

• Bet: Edge 2–8%, fair odds from a reliable sharp reference (Pinnacle, Betfair closing line)
• Skip: Edge below 2% — within the margin of error of the sharp reference
• Verify manually: Edge above 8% — likely stale odds, not genuine mispricing
• Skip: Market vig above 8% — bookmaker is pricing with high uncertainty, fair odds are unreliable

Kelly Criterion Calculator

Calculate optimal stake size using full, half, quarter, or eighth Kelly.

What Kelly does

The Kelly Criterion is a staking formula that maximises long-term bankroll growth by sizing each bet proportionally to its edge. It was developed by John L. Kelly Jr. at Bell Labs in 1956 and is the mathematical foundation of professional sports betting staking. The Kelly Criterion formula for optimal stake is f = (bp - q) / b, where b is the decimal odds minus 1, p is the win probability, and q is 1 minus p.

Example: Odds 2.10, fair probability 52% (p = 0.52, q = 0.48, b = 1.10). Kelly = (1.10 × 0.52 − 0.48) / 1.10 = (0.572 − 0.48) / 1.10 = 0.0836 = 8.36% of bankroll. Quarter Kelly = 2.09% of bankroll. On a £1,000 bankroll: £20.90 stake. See Wikipedia's Kelly criterion article for the full mathematical derivation.

Full vs half vs quarter Kelly

Quarter Kelly is the standard recommendation for football value bettors. It produces approximately 75% of full Kelly's long-term growth rate while reducing maximum drawdown from 50%+ to under 15%. The psychological benefit — surviving losing streaks without abandoning the strategy — is as important as the mathematical benefit.

No-Vig Fair Odds Calculator

Strip the bookmaker's margin to reveal true implied probabilities and fair odds.

What "vig" is

The vig (vigorish, juice, or margin) is the bookmaker's built-in profit margin. On a fair 50/50 coin flip, fair odds are 2.00 on both sides. A bookmaker offering 1.90/1.90 has a vig of 5.26% — the combined implied probability is (1/1.90 + 1/1.90) = 105.26%. The 5.26% excess is the bookmaker's edge. Removing the vig reveals the true probability the bookmaker believes each outcome has.

4 vig removal methods

Fair odds can be calculated four ways — additive, multiplicative, power, and Shin — with the Shin method being most accurate for low-vig markets and additive for high-vig 2-way markets.

For most football betting purposes, the additive method is sufficient. Use the Shin method when you need the most accurate true probability estimates — for example, when building your own pricing model or when comparing against Pinnacle's no-vig lines.

Why sharp bettors devig everything: Comparing your odds directly to a soft book's implied probability includes the bookmaker's margin. A bet at 2.00 on a market with 5% vig is not a 50% probability bet — it is a 47.6% probability bet. Devigging first gives you the true probability, which is the correct input for edge calculation and Kelly staking.

Closing Line Value (CLV) Calculator

Measure whether your bets are beating the market — the #1 leading indicator of skill.

Closing line value (CLV) is the percentage difference between the odds you took and the odds at market close, and is the strongest single predictor of long-term betting profitability. If you consistently beat the closing line, your edge is real - even if your short-term P&L is negative due to variance.

Why CLV matters more than P&L: P&L over 100 bets is dominated by variance. CLV over 100 bets is a statistically meaningful signal. A bettor with +2% average CLV and −5% P&L over 100 bets is almost certainly profitable - they just need more volume for the edge to manifest. A bettor with −2% average CLV and +10% P&L over 100 bets is almost certainly losing - they got lucky. Track CLV from your first bet.

Frequently Asked Questions