// Free tool · Models, figures and props
Model scale calculator
To find a size at scale, divide the real size by the scale number: at 1/6 scale, a 180 cm person is 30 cm (11.8 in) tall. To scale a 3D print, divide the size you want by the size it is now and multiply by 100 for your slicer's percentage. Both are worked out below, in metric or inches.
How tall is a person at each scale?
A 180 cm (5 ft 11 in) person at common model, figure and toy scales.
| Scale | cm | mm | inches |
|---|---|---|---|
| 1:2 | 90.0 cm | 900 mm | 35.43 in |
| 1:3 | 60.0 cm | 600 mm | 23.62 in |
| 1:4 | 45.0 cm | 450 mm | 17.72 in |
| 1:6 | 30.0 cm | 300 mm | 11.81 in |
| 1:8 | 22.5 cm | 225 mm | 8.86 in |
| 1:10 | 18.0 cm | 180 mm | 7.09 in |
| 1:12 | 15.0 cm | 150 mm | 5.91 in |
| 1:18 | 10.0 cm | 100 mm | 3.94 in |
| 1:24 | 7.5 cm | 75 mm | 2.95 in |
| 1:32 | 5.6 cm | 56 mm | 2.21 in |
| 1:35 | 5.1 cm | 51 mm | 2.02 in |
| 1:43 | 4.2 cm | 42 mm | 1.65 in |
| 1:48 | 3.8 cm | 38 mm | 1.48 in |
| 1:64 | 2.8 cm | 28 mm | 1.11 in |
| 1:72 | 2.5 cm | 25 mm | 0.98 in |
| 1:87 | 2.1 cm | 21 mm | 0.81 in |
| 1:144 | 1.2 cm | 12 mm | 0.49 in |
How it's worked out
- Size at scale = real size ÷ the scale number. At 1:6, 180 cm ÷ 6 = 30 cm.
- Real size = size at scale × the scale number.
- Slicer percentage = size you want ÷ size now × 100, or old scale number ÷ new scale number × 100.
- Inches are converted at exactly 25.4 mm.
Scaling a helmet to fit your head is a different sum, because the inside has to clear your head plus padding: the helmet size calculator does that one. Too big for your printer? See the printer guide for bed sizes.
Scale questions
What is 1/6 scale?
1/6 scale (also written 1:6) means the model is one sixth the size of the real thing: every 6 cm of the real object is 1 cm on the model. It's the usual scale of 12-inch action figures, because a 6 ft person is 12 inches tall at 1/6.
How big is 1/6 scale?
A 180 cm (5 ft 11 in) person is 30 cm, or 11.8 inches, tall at 1/6 scale. For any size, divide the real size by 6; the calculator does it for every common scale.
How do you calculate scale?
Divide the real size by the scale number to get the model size, or multiply the model size by the scale number to get the real size. To find the scale from two sizes, divide the real size by the model size: a 2 m object shown as 10 cm is 1:20.
How do you scale a 3D print to a specific size?
Divide the size you want by the model's current size in your slicer and multiply by 100: that's the percentage to enter. To change scale instead, divide the file's scale number by the scale you want: a file made at 1/6 printed at 1/4 needs 150%. Keep the scale uniform so the proportions stay right.
What scale are 6-inch figures?
About 1/12, since a 6 ft character is 6 inches tall at 1/12. Lines that sell 6-inch figures size their characters slightly differently, so treat it as a close guide rather than an exact rule.