MDF & Bet Sizing Calculator
Enter the pot and the bet. The calculator shows how often you must defend against that bet (MDF), how often a bluff must work to break even, and how many bluffs a balanced betting range holds.
Chips in the middle before the bet you face or make.
The bet in the same units as the pot.
- Minimum defence frequency
- 66.7%
- Folds a bluff needs
- 33.3%
- Equity the caller needs
- 25%
- Bluffs in a balanced bet range
- 25%(0.33 bluffs per value bet)
Standard bet sizes for this pot
| Bet, % of pot | MDF | Bluff folds needed | Bluff share |
|---|---|---|---|
| 25% | 80% | 20% | 16.7% |
| 33% | 75.2% | 24.8% | 19.9% |
| 50% | 66.7% | 33.3% | 25% |
| 66% | 60.2% | 39.8% | 28.4% |
| 75% | 57.1% | 42.9% | 30% |
| 100% | 50% | 50% | 33.3% |
| 150% | 40% | 60% | 37.5% |
| 200% | 33.3% | 66.7% | 40% |
Single street, no raises. MDF is a guide for the whole range, not for one hand; against opponents who bluff too little you can fold more.
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How the numbers are built
MDF = pot / (pot + bet). It is the share of your range that must continue against a bet; fold more and a bluff profits automatically whatever cards it holds.
The fold share a pure bluff needs is bet / (pot + bet). It always equals 1 − MDF: the two are the same fact seen from both sides of the bet.
The caller needs bet / (pot + 2 × bet) equity. In a balanced range that is also the bluff share of the betting range, which is why bigger bets can hold more bluffs.
Worked example
The pot is 100 and the bet is 50 (half pot). MDF = 100 / 150 = 66.7%, so you continue with about two thirds of your range. A pure bluff needs 50 / 150 = 33.3% folds.
The caller needs 50 / 200 = 25% equity, so a balanced half-pot range holds 25% bluffs: one bluff for every three value bets.
Questions and answers
What is MDF in poker?
Minimum defence frequency: the share of your range you must continue with against a bet so that the bettor's bluffs cannot profit automatically. It equals pot / (pot + bet).
Should I always defend exactly MDF?
No. MDF is a reference for the whole range. Against players who bluff too little, fold more; against players who bluff too much, defend more. It also ignores raises and later streets.
Why do bigger bets need fewer defends?
A bigger bet risks more to win the same pot, so a bluff needs more folds to pay off, and the caller can fold more often without becoming exploitable.
How many bluffs should I bet with?
In a balanced range the bluff share equals the equity the caller needs: 25% at half pot, 33% at pot size, 40% at 1.5 times pot. Adjust to how often your opponent folds.
Related guides
Poker is a game of skill and chance. The calculator is an educational tool and does not guarantee results. Play responsibly: responsible gambling.