The MTG deck probability calculator uses the hypergeometric distribution to calculate the exact probability of drawing a specific number of copies of a card in your opening hand. Essential for optimizing deck consistency.
Deck Parameters
Opening Hand Odds — 60-Card Deck, 7-Card Hand
| Copies in Deck | P(≥1) | P(≥2) | P(0) |
|---|---|---|---|
| 1 copy | 11.7% | 0.7% | 88.3% |
| 2 copies | 22.2% | 2.7% | 77.8% |
| 3 copies | 31.6% | 5.9% | 68.4% |
| 4 copies | 39.9% | 10.2% | 60.1% |
How to Use the MTG Deck Probability Calculator
Deck consistency is the foundation of competitive Magic: The Gathering. This MTG deck probability calculator uses the hypergeometric distribution to show exact opening-hand odds so you can make data-driven decisions about how many copies to run.
Step 1: Set your deck parameters
Choose your deck format (60-card for Standard/Modern, 100-card for Commander, 40-card for Limited). Set the hand size to 7 for opening hand probability, or lower for mulligan scenarios. Enter how many copies of the card you're testing.
Step 2: Interpret the results
For a key card you want to see every game: running 4 copies in 60 cards gives a 40% opening-hand rate — you'll have it in roughly 2 of every 5 games. Running 8+ cards that perform a similar function (e.g., 4 Thoughtseize + 4 Inquisition) effectively gives you an 80%+ chance of seeing at least one disruption spell.
Step 3: Apply to mana base design
The most common use of probability math in MTG is mana base construction. If you need two blue mana by turn 2, calculate how many blue sources you need to achieve 90%+ consistency. The standard formula: 24 lands for consistent 2-land opening hands (95%+ with 7-card hand).
FAQ
Is this MTG probability calculator free?
Yes, completely free with no account required.
Is my data safe?
Absolutely. All calculations run in your browser — no data is sent to any server.
What is the hypergeometric distribution?
The hypergeometric distribution calculates the probability of drawing a specific number of 'successes' from a finite population without replacement. In MTG, it's used to calculate the probability of drawing exactly N copies of a card in your opening hand, given how many copies are in your deck.
How many copies should I run to reliably see a card?
To see at least 1 copy in your 7-card opening hand: 1 copy gives ~12%, 2 copies ~22%, 3 copies ~32%, 4 copies ~40% chance. For a 'must-have' card you want in every game, run 4 copies. For situational cards, 2 copies is typically sufficient for consistency.
How does the mulligan rule affect probability?
The Vancouver Mulligan (draw 7, put 1 on bottom) and London Mulligan (draw 7, put any cards on bottom equal to mulligans taken) both significantly improve your odds of seeing key cards. The London Mulligan in particular makes 1-2 of copies of key cards much more reliable than raw math suggests.
Does this work for Commander (100-card deck)?
Yes — set the deck size to 100 and the hand size to 7. Commander probability is much lower per copy since you only run 1 of each card, so the calculator helps you understand how often you'll see your commander on curve vs. needing to cast from the command zone.