MTG Mana Base Guide: The Land Count Formula Explained

The one rule this MTG mana base guide would give you: run Frank Karsten's formula first, then look for a reason to break it. For a 60-card deck that means 19.59 + (1.90 x the average mana value of your spells), which puts a typical constructed deck somewhere between 23 and 27 lands. The 17 you hear about is a 40-card Limited number. Below we work through the formula, check it against what Standard Challenge players actually registered this October, and then handle colors as a separate problem, because a deck with the right number of lands can still have the wrong ones.

The short version of what real decks do: nearly half sit within a land of the formula, and most of the rest run fewer lands, not more. The ones far below it (Izzet at 20) are full of cantrips and spells that cost less than their printed mana value. The ones above it want land drops for their own sake.

How Many Lands Should a Magic Deck Run?

Work it out from your own list, not from the label on the deck. Add up the mana value of every nonland card, divide by the number of nonland cards, and put that average into the formula below. An aggressive deck that spends the whole game casting cheap spells will come out lower than a control deck that has to keep making land drops while it holds up answers, and that is the point: the count describes what your deck does.

Keep the second job separate. How many lands is a curve question. Which colors those lands make is a pip question (the colored mana symbols in your spells), and a deck can get the first one right and still lose to a hand of the wrong colors. If test games keep missing land drops, add a land or lower the curve. If lands pile up in hand while the spells are cheap, trim one at a time.

The Frank Karsten Land Count Formula

Frank Karsten's land count comes out of real tournament decks rather than a round number someone liked. For a 60-card deck, the base land requirement is:

19.59 + (1.90 x Average Mana Value)

Average Mana Value, or AMV, is the mana value of every nonland card added up and divided by the number of nonland cards. Lands stay out of it.

Here's the formula worked through with a deck whose Average Mana Value is 2.8:

19.59 + (1.90 x 2.8)
= 19.59 + 5.32
= 24.91

That comes to about 25 lands after rounding.

*Video: "How Many Lands Should You Play?", episode 3 of Karsten's Magic Math series, published on the TCGplayer channel.*

Karsten built this formula through least-squares regression on more than 95,000 winning decks from MTG Melee and Magic Online events (July 2020 to July 2022) rather than guessing at round numbers, which is why it holds up better than flat "run 17 lands" advice. The full method is in Karsten's updated land analysis on TCGplayer, which also subtracts 0.28 land for every cheap card draw or ramp spell. For an average mana value of three he says to start with 25 or 26 lands and cut one land for every three or four of those spells. His Commander article covers the Commander side in more depth.

Every mana base starts with basic lands like this Forest, the simplest possible single-color source. Image: card scan by Wizards of the Coast, source Scryfall.

GODEEPER: Color identity determines which lands and colored spells a Commander deck can even run. MTG Color Identity Explained: What Actually Counts →

Land Count by Archetype

Put three typical curves through the formula for a 60-card deck and you get this:

Image: BaseMTG chart. Source: arithmetic on the formula in the section above, formula from Frank Karsten's TCGplayer land analysis, checked October 9, 2026.

Even the aggro row says 23, not 17. The 17 is a 40-card Limited number. A midrange deck with a low curve lands near the aggro row and an aggro deck with expensive top-end creeps toward midrange, so run your own list's average instead of picking the row by its label. The next section shows how far real decks move from these numbers.

What Real Standard Decks Play Against the Formula

We checked the formula against the decks people actually register. We took every 60-card main deck from the ten MTGO Standard Challenges of October 8 to 15, 2026, looked up each card on Scryfall, worked out each list's average mana value and compared the formula's answer with the lands in the list. The script and its output are in our repo (data/sims/2026-10-17-mana-base/).

Image: BaseMTG chart. Source: 291 MTGO Standard Challenge lists, October 8 to 15, 2026 (mtgo.com), card data from Scryfall, formula from Frank Karsten.

The typical list plays about one land under the formula. That fits Karsten's own correction: his regression takes just over a quarter of a land off for every cheap card draw or ramp spell, and most competitive decks carry a few. In total, 120 lists sit at least one land below the formula, 136 within one land of it, and only 35 at least one land above.

Izzet is the extreme case, and it is not breaking the math so much as fooling it. Every Izzet list with the two cantrips runs four Sleight of Hand and nearly all run four Opt, which is already two lands off on Karsten's correction. The rest comes from cards whose printed mana value is fiction. Half the lists play four Sunderflock, a nine-mana card that costs X less where X is the greatest mana value among your Elementals; Hearth Elemental and Eddymurk Crab both shrink with every instant and sorcery in the graveyard. Those cards drag the average up to about three, the formula asks for 25, and the deck plays 20. If your deck doesn't discount its own top end, don't copy the 20.

The two groups above the formula are there on purpose. Green landfall plays 26 lands because Mossborn Hydra doubles its counters whenever a land enters, so a late land is a spell, and it still runs Llanowar Elves on top: the ramp creature didn't cost the deck a land. White control plays 26 because it has to keep hitting land drops to cast four-mana sweepers like Day of Judgment and still leave answers up afterwards.

Commander Mana Bases Work Differently

Commander is a 100-card singleton format. For a deck at normal precon power, start at 37 to 40 lands plus 10 to 12 dedicated ramp spells.

Players building Commander decks reach the same conclusion in their own words. In an August 24, 2026 r/EDH thread titled "Factors that influence the number of lands", one commenter wrote:

"I think card draw is the biggest factor but also the deck archetype. If you play aggro you have a low mana curve and want to out things fast. So less lands and more fuel." (u/komigerTyp on r/EDH)

For a 99-card deck, Karsten's analysis gives 31.42 + 3.13 x AMV minus 0.28 per cheap card draw or ramp spell, which is 40 or 41 lands at an AMV of three before any ramp credit. Ten to twelve ramp spells take roughly three lands off that, which is where the 37-40 range comes from. We'd still count the ramp at less than a full land: a Sol Ring can be destroyed, a land in play rarely is.

How Many Lands of Each Color?

Count the colored mana symbols, or pips, in the spells you want to cast in your first few turns, and build the color split from those, not from how many cards of each color you play. A color with ten cards that mostly cost generic mana needs fewer sources than a color with four double-pipped two-drops.

Karsten worked out the exact numbers in his 2022 colored-sources update on TCGplayer: how many sources of one color a deck needs to cast a spell on curve, on the play, about 90 percent of the time. A few rows from his table, where "C" is one colored symbol:

The table explains why two-color aggro decks stretch: a CC two-drop wants 21 sources of its color in a 60-card deck that only has 23 or so lands. For a gold card, Karsten works out each color on its own and then adds one to every number. Only untapped lands count toward a turn-one play, and his rough ceiling is three tap-lands in a 60-card aggro deck with one-drops and nine in a midrange or control deck without them.

A fixing land like Fabled Passage can cover more than one color requirement, unlike a basic land. Image: card scan by Wizards of the Coast, source Scryfall.

A mono-colored deck skips this math entirely; see our Mono-Green Landfall Standard deck guide for a worked example of that advantage.

GODEEPER: Fast mana and mana rocks can substitute for some of your land count once your curve calls for acceleration. cEDH Staples Guide: Fast Mana, Tutors, and Interaction →

Steps to build a mana base, in order

1. Calculate your Average Mana Value. Add up the mana value of every nonland card, then divide by the number of nonland cards.

2. Apply the Karsten formula. Plug your average into 19.59 + 1.90 x AMV for a 60-card deck, then take off a land for every three or four cheap cantrips or ramp spells, as Karsten suggests.

3. Count your colored pips separately. List the spells you want to cast in your first three turns and check each color against the sources table above.

4. Adjust for format. For Commander, start from 37 to 40 lands plus 10 to 12 ramp spells instead of the 60-card numbers.

5. Test before you cut. Go under the formula only for one of the reasons in the next section.

When We'd Leave the Formula

Run the formula's number unless you can name the card that lets you skip a land. Four Opt and four Sleight of Hand are a reason. Sunderflock and Eddymurk Crab are a reason, because nobody pays full price for them. "My deck is aggro" isn't one: the low-curve lists in those Challenges still played around 21, not 17. Go above the formula only when lands do something for you, the way landfall decks and draw-go control decks use them. And if you're torn between two numbers in a 60-card deck, play the higher one for your first ten games and cut only when you keep drawing too many.

Related Reading

• MTG Commander Deck Guide: Building, Budget, and cEDH: the full Commander deckbuilding rules this mana base guidance feeds into.
• Budget Commander Decks Under $50: how a functional mana base fits into a budget Commander build.
• Standard Metagame Tier List After Reality Fracture: the decks behind the land counts in our table, tier by tier.

References

• What's an Optimal Mana Curve and Land/Ramp Count for Commander?, Frank Karsten for Channel Fireball
• How Many Sources Do You Need to Consistently Cast Your Spells? A 2022 Update, Frank Karsten on TCGplayer
• Standard Challenge decklists, Magic Online
• MTG Land Calculator: Mana Base for 40, 60 & 100-Card Decks, Draftsim
• Everything You Ever Needed to Know About Mana Curves in Magic, Draftsim
• The Basics of Mana, Wizards of the Coast