🌐 EN

📄 Origami Paper Size Calculator

Enter your desired finished model size (cm) and pick a model to estimate the required starting paper size.

Required Paper Size
Ratio Used

per square paper side

Related Calculators Craft Pricing Calculator Paint Color Mixing Calculator Hair Dye Mixing Calculator
GUIDE

Learn more

01

How to Work Backward From Finished Size to Paper Size

An origami model's finished size scales roughly proportionally with the starting paper size. This calculator uses finished size ÷ ratio = required paper side length. For example, if you want a crane with an 11cm wingspan and the crane's ratio is 0.55, the required square paper side is 11 ÷ 0.55 = 20cm.

ModelApprox. finished-size/paper-side ratioNotes
Crane0.55square paper
Masu box0.50square paper
Butterfly0.45square paper
Sailboat0.60square paper
Lucky star (5-point)0.12not square — measured against paper strip length

These ratios are not an exact geometric law — they are approximate figures commonly cited within origami-hobbyist references for typical traditional diagrams. Actual results vary by paper thickness, fold precision/tightness, and the specific diagram/variant used, so treat them as a starting estimate and adjust based on a test fold.
02

Why Is the Lucky Star Different?

Most origami models are measured against a square paper side, but the 5-point lucky star is typically folded and knotted from a long, narrow paper strip instead of a square. Its "size" usually refers to the point-to-point diameter of the finished star, which is roughly 1/8 of the strip length used. So when you select the lucky star preset, the calculated "required paper size" should be read as the required strip length, not a square side. For example, to get a 3cm-diameter star, you'd need a strip roughly 3 ÷ 0.12 = 25cm long.

Frequently asked questions

Are these ratios an exact formula?
No. These ratios are not an exact geometric law — they are approximate, commonly cited community figures for typical traditional diagrams. Actual results vary by paper thickness, fold precision, and the specific diagram/variant used, so treat this as a starting estimate and adjust with a test fold.
Why does the lucky star calculate differently?
The lucky star is folded from a long paper strip, not a square. Its "size" refers to the point-to-point diameter, which is roughly 1/8 of the strip length used. So for this preset, the result represents the required strip length, not a square paper side.
How do I find my own custom ratio?
If you have already folded a model once, divide the finished size by the paper side (or strip length) you used to get your own ratio, then enter it under "Custom Ratio" for accurate results at other sizes.