Opening-hand land calculator
How often will your opening hand have the lands you want? Check exact odds before changing your deck.
Your chance of 2–4 lands
74.84%
In 7 cards drawn from a 99-card library with 37 lands.
2.62 expected lands per draw of 7 cards
Exact probabilities, rounded to two decimal places. Very small chances may display as 0.00%.
A single random draw, without replacement. No mulligans, scrying, tutors, mana rocks or coloured mana requirements are included.
How to calculate your land-draw odds
- Enter the number of cards actually in your library. Exclude your commander or commanders.
- Count the cards you want to treat as lands, then enter how many cards you will draw.
- Choose an inclusive range, such as 2 to 4 lands in a seven-card hand, and calculate.
The default example is a 99-card library containing 37 lands. It is an example to explore, not a recommended land count for every Commander deck. For two commanders starting outside the library, enter 98 if the full deck contains 100 cards.
What the numbers mean
The large result adds the probabilities for every land count in your chosen range. The breakdown gives the chance of each exact count. Expected lands is an average over many draws; an actual hand always contains a whole number.
This uses the hypergeometric model: P(X = k) = C(L, k) × C(N − L, n − k) / C(N, n), where N is library size, L is land count and n is cards drawn. Cards are drawn without replacement from a uniformly shuffled library. The implementation uses equivalent step-by-step probabilities to avoid very large factorials.
Questions about opening hands
Does this account for mulligans?
No. It models one random draw. London mulligans involve drawing and choosing cards to put back, so a kept hand depends on your decisions. Simply lowering cards drawn does not model that process.
How should I count modal double-faced cards?
Decide which cards you want to classify as lands for this calculation and count each card once. The model cannot account for choosing between a spell and land face, tapped lands or coloured mana requirements.
Can I check later draws?
Yes, for an unconditional total number of cards seen without selection effects, increase Cards drawn. If you already know some cards, remove those cards and their lands from the library counts and model only the future draw. This is not a turn-by-turn simulator.