Altitude is commonly expressed as a number defining the distance in layers above the base of the game environment, which is layer zero (0). Sea level is recognized as layer 62 (i.e. altitude 63), and the top of the game environment is layer 255 (i.e. altitude 256). Clouds appear halfway between the two at layer 127.
More specifically, the bottom face of the bottommost bedrock block is at Y-coordinate 0, and the top face of the highest block that can be placed is at Y-coordinate 256. The player can press F3 to see the Y-coordinate of the top face of the block on which they are standing or of their eyes, with the player's eyes located about 1.6 blocks above the layer on which the player is standing. For example, a player standing on a shore of an ocean will see the Y-coordinate of their eyes as approximately 64.6.
 Natural resources and altitude
Features in the landscape of the Overworld are found at different altitudes, as shown in this graph.
There is also an interactive chart. Beware the logarithmic scale: a slight difference in the Y-coordinate means a large change in relative frequency of this block type. Some observations:
- Looking at water, the ocean level at layer 62 is obvious. Going down, the amount decreases more quickly at layers 56 and 48, the usual depth of river and ocean biomes respectively. There are corresponding peaks in the amount of clay beneath them. (Note that clay can occasionally be generated even in high-altitude lakes.) Between layers 33 and 12, most water is falling down sub-ocean ravines, spreading out on the lava-filled bottom at layer 10 and producing most of the naturally-occurring obsidian.
- Ores and gravel (not shown) usually occur as a fixed percentage of the amount of stone (also not shown), tapering off at the ends of their allowed range. This is why coal and iron follow parallel tracks between layers 5 and 60.
- The one exception is lapis lazuli ore, which has a linear progression up to a peak at layers 13-14.
See the following table for a textual description of resources by altitude and tools needed to gather them.
|Landscape Feature||Complete range||Commonly found between||Ideal layer||Implement needed to obtain|
|Coal ore||Layers 0-114||Layers 5-66||Layer 48||Pickaxe|
|Gravel||Layers 1-115||Layers 5-56||Layer 48||None|
|Dirt (including Grass and Mycelium)||Layers 0-126||Layers 5-80||Layer 61||None|
|Sand||Layers 2-112||Layers 43-63||Layer 61||None|
|Water||Layers 1-111||Layers 48-62||Layer 62||Bucket|
|Iron ore||Layers 0-63||Layers 2-58||Layer 42||Stone or better pickaxe|
|Gold Ore||Layers 0-31||Layers 4-29||Layer 28||Iron or better pickaxe|
|Lapis Lazuli ore||Layers 0-30||Layers 11-17||Layer 14||Stone or better pickaxe|
|Lava||Layers 0-85||Layers 4-10||Layer 10||Bucket|
|Obsidian||Layers 2-62||Layer 10||Layer 10||Diamond pickaxe|
|Emerald Ore||Layers 4-32||Layers 4-29||Layer 20||Iron or better pickaxe|
|Diamond Ore||Layers 0-15||Layers 4-13||Layer 13||Iron or better pickaxe|
|Redstone Ore||Layers 0-15||Layers 4-13||Layer 12||Iron or better pickaxe|
|Bedrock||Layers 0-4||Layers 0-2||Layer 1||Only breakable in Creative Mode|
- The range in which the block can be found in the map used for the graph.
- The layer where getting that resource is easiest. We consider the amount of lava/water lakes, the amount of caves, the altitude (and whether it is at the surface), and the amount of gravel/sand.
- Redstone has the same layer and line-size statistics as Diamond, but is generated 8 times per chunk as opposed to 1.
Other naturally occurring features appear at different altitudes such as grass, wood, flowers, mushrooms, clay, cobblestone, sugar cane and Obsidian, but all of these features are random and will only appear in conjunction with another block and the proper environment.
|Grass||Dirt, Light and Grass|
|Sugar Cane||Dirt or Sand (as of beta 1.8) and Water|
|Wood||Dirt, Light and a sapling|
|Flowers||Dirt and Light|
|Mushrooms||Dry land and darkness|
|Obsidian||Lava source and Water|
|Cobblestone||Lava and Water, Dungeons and Jungle Temples|
|Mossy Cobblestone||Dungeons, Jungle Temples and Tagia Forests|
 The Nether
A similar graph, showing the distribution of blocks unique to the Nether:
|Landscape Feature||Complete range||Commonly found between||Implement needed to obtain|
|Netherrack||Layers 1-126||Layers 4-123||Pickaxe|
|Soul Sand||Layers 14-81||Layers 58-64||None|
|Glowstone||Layers 2-120||Layers 98-106||None|
|Nether Brick||Layers 19-86||Layers 48-66||Pickaxe|
|Nether Quartz Ore||Layers 7-117||Layers 9-115||Pickaxe|
 Pocket Edition
The height limit on Pocket Edition is half as much as the computer version (identical to the height limit before the Anvil file format).
|Highest water level||64|
|Highest Bedrock layer||9|
|Void||0 or below|
 The Nether Reactor
Nether Spire is a room which is a size of 7x17x17 Note: Spawning Items is spawned Layers 3-7.
|Landscape Feature||Complete range||Commonly found between||Implement needed to obtain|
|Netherrack||Layer 1-17||Layer 1-17||Any pickaxe|
|Glowstone Dust, Nether Quartz, Doors, Sugar Canes, etc.||Layers 3-7||Layers 3-7||None|
- Pre-Alpha: Players could build 32 blocks up from sea level or dig 32 down for a total of 64 blocks height (numbered 0-63 presumably).
- As of Alpha solid blocks could be placed from layer 0 to layer 127.
- As of Beta 1.6, solid blocks could no longer be placed on layer 127. However, beds, signs, torches and other non-solid blocks could be placed on layer 127.
- As of Beta 1.6, entities are no longer invisible when above the build limit, however, they are black (like if they were in darkness).
- As of the Beta 1.8 Pre-Release, the player's view distance decreases in lower altitudes.
- As of the Beta 1.8 Pre-Release, entities are no longer black when above the build limit.
- Before Beta 1.8, the sea level was at layer 63 instead of 62. Players who have maps created before this update will find one-block-high "waterfalls" at the edges of the terrain previously generated when moving into new, post-Beta 1.8 terrain.
- Previously, In Creative Mode, players could fly above this level, but were not able to build above it. Note that sea level was already layer 62 before the update, so the height of the actual terrain did not change. This change in height was introduced along with the switch from the Region file format to the new Anvil file format, which was implemented in 12w07a.
- Release 1.2.1: Height limit doubled (0-255 instead of 0-127).
- Release 1.7.2: AMPLIFIED world type added, which makes almost every biome generate to extreme heights (attempts to use the full 255 height).
- Above about Y=240, when you can see the horizon on "normal" render distance, the sun and moon are visible during day and night at the same time - only works at around sunset and sunrise.
- The Beta 1.6 update made it impossible for players to place blocks on the uppermost layer of the map (Y=127).
- At extreme depths, black Void fog closes in.
- A similar darkening can be found on the highest layer that can be built on.
- Although the highest possible altitude the player can climb normally is Y=257 (door "glitch" + jumping), a TNT cannon can blast the player many layers past the sky limit.
- Going under Y=-64 in the Void will cause the player to receive damage very quickly, killing him/her. Also, this is the only way to die in Creative mode (except the /kill command).
- Although blocks cannot normally be placed past Y=254, there are several exceptions:
- Beds, along with other non-solid blocks (Signs, Torches) can be placed on the 255th layer. Also, if a door is placed 1 layer below the top of the map, its upper frame will pass the 254th mark.
- By placing a water source block on layer 255 using a Water Bucket on a solid block on layer 254, then placing a lava source block on the water using a Lava Bucket, both Cobblestone and Obsidian can be created on layer 255. The opposite (placing water on lava) works as well.
- Placing a rail, flat snow, etc. block on the 255th layer, then trying to place a block on it will give you the message: Height limit for building is 256. This also applies when trying to place a block on top of a solid block at layer 255 (using MCEdit, or water and lava).
- Notch, on his Twitter feed before the Adventure Update, posted a picture showing his experimentation with height limits and terrain generation up to 512, featuring a mountain much higher than normal mountains. The height limit was eventually increased to 256 in 1.2.1, though landforms did not yet generate above layer 127.
- The maximum height (coordinates) a player can reach is displayed as "6.7108E7" Example 1 Example 2 (6.7E7 is 6.7 times 10^7th, or 67 million, approximately 2^26th)
- The highest achievable height in Xbox Edition is y=511.
- The Nether Reactor has a height limit. Attempting to build it too high will result in the game scolding you and saying "The nether reactor needs to be built lower down".
- In 14w03b(Release 1.8), going too high up in the game will say ""Connection Lost Illegal Stance" and you can't even load the world.
- If you go much above the 255th layer while it is raining the rain will change the rain into snow, giving evidence that some of Minecraft is based on real life science.