Building a Nether portal is one of the most important milestones in Minecraft. It marks the player’s transition from the Overworld into the dangerous and resource-rich Nether dimension. However, many players—especially beginners—often ask the same question before they start mining: how much obsidian is actually required to build a Nether portal? The answer depends on the portal size, whether corners are included, and whether the player chooses a minimal or decorative design.
TLDR: A standard Nether portal requires 10 obsidian blocks if built without corner blocks, or 14 obsidian blocks if built as a full rectangular frame. Larger portals can use up to 23 obsidian blocks for the maximum usable size. Decorative variations can require even more. Understanding frame rules helps players save time, tools, and diamonds.
Standard Nether Portal Requirements
The most common Nether portal size is a 4-block tall by 5-block wide frame. This creates an interior portal area of 2 blocks wide and 3 blocks tall where the purple portal field appears.
Here’s how the block count works:
- 4 blocks tall on each side (8 blocks total)
- 3 blocks across the top
- 3 blocks across the bottom
This equals 14 obsidian blocks if the portal is built as a complete rectangle.
However, Minecraft does not require the four corner blocks to be obsidian. The corners can be removed or replaced with other blocks (or left empty during construction). This reduces the required amount to:
- 10 obsidian blocks total
This “cornerless” method is the most resource-efficient build and is especially popular in survival mode when obsidian is limited.
Minimum Obsidian Needed: 10 Blocks
The absolute minimum amount of obsidian required to create a functional Nether portal is 10 blocks. This is achieved by building:
- 2 vertical columns of 4 obsidian blocks each (8 blocks)
- 1 obsidian block at the top center
- 1 obsidian block at the bottom center
This configuration leaves all four corners empty but still satisfies the game’s portal activation mechanics.
Why does this work?
Minecraft only checks for a complete rectangular frame surrounding a hollow interior space. The engine does not require the frame corners to be made of obsidian specifically.
Tip: Speedrunners and experienced survival players almost always use the 10-block version to conserve valuable diamond pickaxe durability.
Full Frame Version: 14 Blocks
Some players prefer the aesthetic of a complete rectangular frame. In that case, the portal requires 14 obsidian blocks.
This version:
- Looks symmetrical and finished
- Is often used in permanent bases
- Works better in decorative or roleplay builds
While it costs 4 extra obsidian blocks than necessary, many players consider the visual upgrade worth it.
Maximum Nether Portal Size
Minecraft allows larger portal frames beyond the standard size. The maximum interior portal size is:
- 23 blocks tall
- 23 blocks wide
This means extremely large portal designs are possible, but they require significantly more obsidian.
For a fully framed maximum portal, the block count would be:
- 23 blocks per side × 2 sides = 46
- 21 blocks along the top
- 21 blocks along the bottom
Total: 88 obsidian blocks
However, just like smaller portals, corner blocks are technically optional. Even so, most players building large portals include full frames for symmetry.
Common Portal Size Variations
Below are some of the most common portal size variations players use in both survival and creative modes:
1. Standard Survival Portal
- Interior: 2×3
- With corners: 14 obsidian
- Without corners: 10 obsidian
2. Tall Portal Design
- Interior: 2×5 or taller
- Block count: 16–20 obsidian
- Used for decorative bases
3. Wide Portal Design
- Interior: 4×3 or wider
- Block count: 18–24 obsidian
- Common in creative builds
4. Maximum Portal Design
- Interior: 21×21
- Full frame: 88 obsidian
- Primarily decorative or cinematic
How to Calculate Obsidian for Any Portal Size
If players want to calculate obsidian for custom portal sizes, they can use this simple formula:
Total Obsidian = (Height × 2) + (Width × 2) − 4 (if removing corners)
Example:
- Frame size: 6 blocks tall × 4 blocks wide
- (6×2) + (4×2) = 12 + 8 = 20
- Cornerless version: 20 − 4 = 16
This formula works as long as the portal meets Minecraft’s minimum requirement of:
- At least 4 blocks tall
- At least 5 blocks wide
Do You Have to Mine All the Obsidian?
Not necessarily.
Players can obtain obsidian in several ways:
- Mining it with a diamond or netherite pickaxe
- Looting ruined portals
- Using lava and water to create it manually
- Bartering (rarely yields obsidian)
Ruined portals are particularly useful because they often provide several obsidian blocks for free. Some speedrunners complete portals by combining ruined portal obsidian with newly created pieces.
Image not found in postmetaEfficiency Considerations in Survival Mode
In early survival gameplay, obsidian is expensive in terms of time:
- Each block takes about 9–10 seconds to mine with a diamond pickaxe.
- Mining requires reaching diamond tier tools.
- Lava lakes must be located safely.
This is why most players aim for the 10-block minimum version.
Extra obsidian should generally be saved for:
- Enchanting tables (requires 4 obsidian)
- Ender chests (requires 8 obsidian)
- Respawn anchors (Nether use)
Wasting obsidian early on decorative corners may delay other critical progression items.
Can Other Blocks Be Used in the Frame?
No. Only obsidian blocks can form the functional portal frame.
However, blocks such as:
- Crying obsidian
- Blackstone
- Deepslate
can be used decoratively around the exterior frame. Crying obsidian, despite its similar appearance, cannot activate a Nether portal.
Activating the Portal
After completing the frame, players must activate it by:
- Using flint and steel
- Using a fire charge
- Triggering fire inside the frame
Once lit, the interior fills with the iconic swirling purple portal texture.
Best Choice for Different Player Types
Beginner Survival Players:
Use the 10-block cornerless version.
Builders and Aesthetic Players:
Use the 14-block full frame or larger custom design.
Creative Mode Players:
Experiment with maximum 23×23 portals.
Speedrunners:
Construct the frame from lava pools using buckets, often without mining traditional obsidian at all.
Final Thoughts
The answer to how much obsidian is needed for a Nether portal ultimately depends on the player’s goals. While 10 blocks is the absolute minimum, many players choose 14 for a complete look. Larger portals expand the possibilities but dramatically increase material costs.
Understanding block counts prevents wasted time and tool durability, especially in survival mode. Whether building a quick gateway to gather blaze rods or constructing a massive decorative entrance to the Nether, knowing the exact obsidian requirements makes the process far more efficient.
FAQ: How Much Obsidian Do You Need for a Nether Portal?
What is the minimum number of obsidian blocks needed?
The minimum required is 10 obsidian blocks using a cornerless 4×5 frame.
How many blocks are needed for a full standard portal?
A complete rectangular frame requires 14 obsidian blocks.
Do the corners of a Nether portal have to be obsidian?
No. The four corners can be left empty or replaced with other blocks, as long as the rectangular shape is maintained.
What is the largest Nether portal you can build?
The maximum size is 23 blocks tall and 23 blocks wide. A fully framed version requires up to 88 obsidian blocks.
Can crying obsidian be used to build a portal?
No. Crying obsidian cannot create or activate a Nether portal frame.
Do you need a diamond pickaxe to mine obsidian?
Yes. A diamond or netherite pickaxe is required to successfully mine obsidian in survival mode.
Can you build a horizontal Nether portal?
No. Nether portals must be built vertically. Horizontal frames will not activate.
Is it better to use 10 or 14 blocks?
For efficiency in survival, 10 blocks is ideal. For aesthetics and permanent builds, 14 blocks may be preferable.