1:20 Scale to 1:50 Scale Conversion
In a metric drawing set, 1:50 carries the floor plans and 1:20 carries the detail drawings — a staircase, a window jamb, a joinery section redrawn exactly 2.5× larger. Students and joiners move between the two constantly: this conversion is how you check that a detail drawn at 1:20 still agrees dimensionally with the 1:50 plan it came from, or resize a component from a 1:50 model for a 1:20 sectional model.
To convert a model dimension from 1:20 Scale to 1:50 Scale, multiply it by 0.4 (20 ÷ 50). The result is a smaller model — every length, width, and height changes by the same factor.
Conversion Chart
| 1:20 Scale size (mm) | 1:50 Scale size (mm) |
|---|---|
| 1 mm | 0.40 mm |
| 2 mm | 0.80 mm |
| 5 mm | 2.00 mm |
| 10 mm | 4.00 mm |
| 20 mm | 8.00 mm |
| 50 mm | 20.00 mm |
| 100 mm | 40.00 mm |
Frequently Asked Questions
How do I convert 1:20 Scale to 1:50 Scale?
Multiply any 1:20 Scale model dimension by 0.4 to get the 1:50 Scale dimension. This works because 1:20 Scale is 1:20 and 1:50 Scale is 1:50, so the factor is 20 ÷ 50 = 0.4.
Is 1:50 Scale bigger or smaller than 1:20 Scale?
1:50 Scale models are smaller: the same subject is only 0.4× the size in each dimension compared to 1:20 Scale.
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Reverse: 1:50 Scale to 1:20 Scale · 1:20 Scale guide · 1:50 Scale guide · Full calculator