The Pod Companion

MTG Mana Base Calculator

How many sources of each color do you actually need to cast your spells on time? Enter your deck size, the color demand of a spell, and the turn you want to cast it. The calculator returns exact hypergeometric odds and a recommended source count.

What a mana base actually is

Most players count lands. Serious deckbuilders count sources of each color. Your land total tells you how often you will hit your land drops. Your color source count tells you how often those lands will produce the colored mana your spells demand on the turn you actually want to cast them. Those are different questions with different answers.

A 24-land deck with 14 blue sources is not the same as a 24-land deck with 10 blue sources. A three-color Commander deck with 38 lands is not the same as a three-color Commander deck with 38 lands where the third color has 9 producers. The lands look identical on a spreadsheet. The games do not.

Rules of thumb by format (starting points, not answers)

These are reasonable starting land counts before the calculator refines them for your specific curve:

Those numbers answer how often will I hit lands. The calculator on this page answers the harder question: how often will the right colors be there when I need them.

How to use this calculator

  1. Set your deck size (60, 40, or 99).
  2. Pick a specific spell in your deck that you want to cast reliably — the one with the tightest color demand is the one that pins your mana base.
  3. Enter the number of colored pips of that color (1 for , 2 for , 3 for triple-pip).
  4. Enter the turn you want to cast it.
  5. Enter how many sources of that color your deck currently runs.
  6. Read the odds. If you are below your comfort threshold, either add sources or push the cast turn one later.

A worked example

You are building a 60-card deck. You want to cast a spell that costs 2 on turn 4, on the play. You are currently running 14 blue sources. Enter deck size 60, pips 2, turn 4, sources 14, on the play — the calculator will tell you your reliability and how many blue sources you would need to hit a 90% threshold. If the answer says 16, that is the honest number. Either shave a colorless land for a dual, cut one of the double-pip spells, or accept that you will fizzle on curve one game in six.

The credit line for the math

The general project of solving Magic mana bases with the hypergeometric distribution was popularized by Frank Karsten's mana base research. His articles are the best further reading if you want the theory behind the numbers. Every value shown on this page is computed live from that same distribution — nothing is copied from a static table.

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FAQ

Does a single pip need fewer sources than a double pip?

Yes. A single-colored cost like only needs one blue source in your opening cards. A double-pip cost like needs two. Because you are asking for two specific matches instead of one, the required source count grows much faster than intuition suggests. The calculator shows the gap numerically.

Does being on the play or on the draw change the number of sources I need?

Slightly. On the draw you see one extra card by the same turn, which raises your odds a few percentage points. For most decks it does not change the recommended source count by more than one, but you can toggle it above.

How do ramp and card draw affect the calculation?

The base calculation assumes a normal draw step per turn. Ramp and extra card draw effectively let you see more cards by your target turn, which improves your odds. A useful shortcut is to set the target turn one higher than the actual cast turn to approximate the effect of one ramp or draw spell.

What about mulligans?

The math assumes a 7-card opening hand with no mulligan, which is the honest floor. Real players mulligan when the opener is unkeepable, so actual reliability is a bit higher than the numbers shown — especially in Commander with the free first mulligan.