<p>LDU stands for <a href="http://www.lugnet.com/~330/FAQ/Build/dimensions" rel="noreferrer">LDraw Unit</a> - the basic unit of measurement in <a href="http://www.ldraw.org/" rel="noreferrer">LDraw</a>, the open standard for LEGO CAD programs, and map to the "Fine" grid setting in applications such as MLCad.</p>

<p>Common measurements include:</p>

<pre><code>1 brick width/depth = 20 LDU
1 brick height      = 24 LDU
1 plate height      =  8 LDU
1 stud diameter     = 12 LDU
1 stud height       =  4 LDU    
</code></pre>

<p><img src="https://i.sstatic.net/t74ys.png" alt="A 1x1 Brick as 3 Plates in LDUs"><br />
A 1x1 Brick as 3 Plates in LDUs (via <a href="http://www.ldraw.org/Article218.html#ldu" rel="noreferrer">LDraw</a>)</p>

<p>The typical LU (LEGO Unit) measurements are coarser at:</p>

<pre><code>Brick height = 6
Plate height = 2
Stud pitch   = 5
</code></pre>

<p>Based on the <a href="https://bricks.stackexchange.com/questions/288/what-are-the-dimensions-of-a-lego-brick">physical dimensions of a LEGO brick</a>, this means that <code>1LDU == 0.4mm</code>, based on a stud height (1LU) of 1.6mm.</p>

CC BY-SA 3.0
2011-11-21T16:42:21.843Z
It might be worth mentioning that this all means (along with the answer to the other question) that 1 LDU = 0.4 mm.
Random832
CC BY-SA 3.0
2011-11-21T16:59:14.620Z
@Random832 consider it done.
Zhaph - Ben Duguid
CC BY-SA 3.0
2011-11-21T14:12:05.160Z
2011-11-21T16:58:43.967Z
2017-04-13T12:47:56.213Z
Zhaph - Ben Duguid
<p>What are LDUs? I see technical people talking about plans and designs in terms of LDUs. I understand it's a measurement unit.</p>

<p>What does it mean and how do LEGO bricks relate to them? Why are they needed?</p>

<terminology><size><ldraw>
What are LDUs and how do they relate to LEGO bricks?
jfyelle
# What are LDUs and how do they relate to LEGO bricks?

(Asked by: username_0 on 2011-11-21)

What are LDUs? I see technical people talking about plans and designs in terms of LDUs. I understand it's a measurement unit.

What does it mean and how do LEGO bricks relate to them? Why are they needed?

**Tags:** terminology, size, ldraw


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## 1 answers

### Answer by username_1 on 2011-11-21. Score: 23 | Accepted answer

LDU stands for LDraw Unit - the basic unit of measurement in LDraw, the open standard for LEGO CAD programs, and map to the "Fine" grid setting in applications such as MLCad.
Common measurements include:
1 brick width/depth = 20 LDU
1 brick height      = 24 LDU
1 plate height      =  8 LDU
1 stud diameter     = 12 LDU
1 stud height       =  4 LDU    


A 1x1 Brick as 3 Plates in LDUs (via LDraw)
The typical LU (LEGO Unit) measurements are coarser at:
Brick height = 6
Plate height = 2
Stud pitch   = 5

Based on the physical dimensions of a LEGO brick, this means that 1LDU == 0.4mm, based on a stud height (1LU) of 1.6mm.

> **Comments:**
> **username_2**: It might be worth mentioning that this all means (along with the answer to the other question) that 1 LDU = 0.4 mm.  
> **username_1**: @username_2 consider it done.  

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