Poker Math Formula Reference

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Definition

Essential mathematical formulas used in poker calculations.

Pot Odds

Formula:

Pot Odds = Call Amount ÷ (Pot + Call Amount)

Example:

  • Pot = $100, Villain bets $50, you must call $50
  • Pot Odds = $50 ÷ ($100 + $50 + $50) = 50/200 = 25%
Bet Size (% of pot) Pot Odds Needed
25% 17%
33% 20%
50% 25%
66% 28%
75% 30%
100% 33%
150% 38%

Equity Required

Break-even Formula:

Required Equity = Risk ÷ (Risk + Reward)

Expected Value (EV)

Formula:

EV = (Win% × Amount Won) - (Lose% × Amount Lost)

Example:

  • 40% to win $200, 60% to lose $100
  • EV = (0.40 × $200) - (0.60 × $100) = $80 - $60 = +$20

Rule of 2 and 4

Situation Multiply Outs By
Flop to Turn 2 (approximation)
Flop to River 4 (approximation)
Turn to River 2 (approximation)

Exact Formulas:

Flop→Turn: Outs × 2.13
Flop→River: Outs × 4 - (Outs - 8)
Turn→River: Outs × 2.17

Common Outs Table

Draw Outs Turn% River% Both%
Gutshot 4 8.5% 8.7% 16.5%
Two overcards 6 12.8% 13.0% 24.1%
Open-ended straight 8 17.0% 17.4% 31.5%
Flush draw 9 19.1% 19.6% 35.0%
Flush + gutshot 12 25.5% 26.1% 45.0%
Flush + OESD 15 31.9% 32.6% 54.1%

Implied Odds

Formula:

Implied Odds = Call Amount ÷ (Pot + Call + Expected Future Winnings)

Minimum Defense Frequency (MDF)

Formula:

MDF = Pot Size ÷ (Pot Size + Bet Size)
Bet Size MDF
33% pot 75%
50% pot 66.7%
66% pot 60%
100% pot 50%
150% pot 40%

Bluff-to-Value Ratio

Formula:

Bluff Frequency = Bet Size ÷ (Pot + Bet Size)
Bet Size Bluff Frequency
33% pot 25% bluffs
50% pot 33% bluffs
66% pot 40% bluffs
100% pot 50% bluffs

Combinatorics Quick Reference

Hand Type Combos
Unpaired (suited) 4
Unpaired (offsuit) 12
Unpaired (total) 16
Pocket pair 6
Pair with 1 blocker 3
Pair with 2 blockers 1

💡 Key Takeaway: Memorizing key formulas and common scenarios speeds up decision-making at the table.

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