Mana Curve & Land Count Calculator
Your land count is a consequence, not a convention. See how often each slot is actually castable — the answers are lower than the advice implies.
How many spells at each cost
Can you actually cast it?
These are lower than most people expect, and they are not typos. Missing a land drop is ordinary — the conventional counts are a compromise between missing drops and flooding out, not an attempt to eliminate the first.
Coloured sources you need
Sources, not lands — anything that produces the colour counts. The jump from one coloured symbol to two is far bigger than from two to three, which is why a single-symbol splash works and a double-symbol one does not.
What this does and does not model
- You miss your land drops far more often than the advice suggests. Twenty-four lands in sixty makes your third drop 79% of the time on the play and your fourth only 63% — those are not typos, and they are the reason a four-drop feels unreliable in a deck that looks perfectly reasonable on paper.
- Getting that fourth drop to nine times in ten would take 33 lands in a 60-card deck. Nobody runs 33, and they are right not to: flooding costs more games than missing a fourth land does. The conventional counts are a compromise between two failures, not a solution to one.
- A curve chart cannot tell you whether the deck functions. Two decks with identical bars can behave completely differently depending on how many lands sit behind them, which is why every slot here is reported with the chance you can actually cast it on time.
- Colour requirements rise much faster than they feel like they should. Adding a second coloured symbol to a cost demands far more sources than the first one did — which is exactly why a deck can splash a single symbol comfortably and cannot splash a double one.
- Mulligans are deliberately not modelled. A player who misses on seven cards takes six, and that raises every probability on this page. Leaving it out makes these figures slightly pessimistic, which is the safe direction to be wrong in when choosing a land count.
- Nor is any card selection modelled — no cantrips, no scry, no fetches, no filtering. All of it helps and none of it is in here, so treat every number as a floor rather than a target.
- The average mana value is the least useful number on this page and the most quoted. It cannot distinguish a deck of twos and fours from a deck of nothing but threes, and those two decks want different land counts.
How to use
- Pick your format and enter how many spells sit at each cost.
- Read the castability column, not the curve shape.
- Compare your land count to the one your critical turn asks for.
Frequently asked questions
How many lands should I run?
It depends on the turn your deck most needs to be functioning, and this computes it rather than quoting a rule. Whatever cost half your spells sit at or below, there is a smallest land count that makes that drop as often as you ask for — and at a realistic target that comes out around the conventional counts, which is a good sign the convention is sound.
How often do I actually make my land drops?
Much less often than the advice implies. Twenty-four lands in sixty makes your third drop 79% of the time on the play and your fourth only 63%. Those are not typos. They are why a four-drop feels unreliable in a deck that looks entirely reasonable written down.
Why not just run more lands then?
Because getting that fourth drop to nine times in ten would take 33 lands in a 60-card deck, and flooding costs more games than missing a fourth land does. The conventional counts are a compromise between two different failures, not an attempt to eliminate one of them.
How many coloured sources does a card need?
Far more than it feels like, and the requirement climbs steeply with each extra symbol. Adding a second coloured symbol to a cost demands several more sources than the first one did, while the third adds fewer — which is exactly why a deck can splash a single symbol comfortably and cannot splash a double one.
Is the average mana value useful?
It is the least useful number on the page and the most often quoted. It cannot distinguish a deck of twos and fours from a deck of nothing but threes, and those two decks want different land counts and behave completely differently. The castability column is what tells you whether the deck works.
Does this account for mulligans?
No, deliberately. A player who misses on seven cards takes six, and that raises every probability here. Leaving it out makes these figures slightly pessimistic, which is the safe direction to be wrong in when you are choosing a land count — but it does mean published source tables sit below these numbers.
What about cantrips, scry and fetch effects?
None of it is modelled. Every form of card selection helps, and none of it appears in these figures, so treat every number here as a floor rather than a target. A deck full of cheap card draw genuinely functions on fewer lands than this will tell you.
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