1:50 Scale to 1:20 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 1:50 Scale to 1:20 Scale, multiply it by 2.5 (50 ÷ 20). The result is a larger model — every length, width, and height changes by the same factor.
Conversion Chart
| 1:50 Scale size (mm) | 1:20 Scale size (mm) |
|---|---|
| 1 mm | 2.50 mm |
| 2 mm | 5.00 mm |
| 5 mm | 12.50 mm |
| 10 mm | 25.00 mm |
| 20 mm | 50.00 mm |
| 50 mm | 125.00 mm |
| 100 mm | 250.00 mm |
Frequently Asked Questions
How do I convert 1:50 Scale to 1:20 Scale?
Multiply any 1:50 Scale model dimension by 2.5 to get the 1:20 Scale dimension. This works because 1:50 Scale is 1:50 and 1:20 Scale is 1:20, so the factor is 50 ÷ 20 = 2.5.
Is 1:20 Scale bigger or smaller than 1:50 Scale?
1:20 Scale models are larger: the same subject is 2.5× bigger in every dimension in 1:20 Scale than in 1:50 Scale.
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Reverse: 1:20 Scale to 1:50 Scale · 1:50 Scale guide · 1:20 Scale guide · Full calculator