Origami Paper GSM to Thickness Calculator

Paper Weight to Thickness Estimation

GSM (grams per square meter) is the universal paper weight standard.
Thickness, also called caliper, depends on density, which varies by paper type.

The simplified relationship: Thickness (mm) ≈ GSM ÷ density factor

The density factor is an empirical number for each paper type (see the table below), not a true material density. For example, 80 GSM kami ÷ 800 = 0.10 mm.

Typical density factors by paper type:

Practical thickness ranges by GSM:

• 30-50 GSM: Tissue, dollar-bill paper. Excellent for complex folds, fragile.
• 60-80 GSM: Kami, tant. Standard origami. Holds creases well.
• 90-120 GSM: Heavy origami, light cardstock. Good for boxes and modular.
• 150-200 GSM: Heavy cardstock. Rigid; better for tato and decorative folds.
• 200+ GSM: Roughly 0.22 mm and up in cardstock, which is usually too thick for traditional folds without scoring first.

Maximum fold count

You have probably heard that no sheet of paper can be folded in half more than seven times. The number is about right for a 15 cm origami square, but the usual explanation for it is wrong. People say the thickness overtakes the length: fold 0.09 mm kami seven times and you get 11 mm, nowhere near the 150 mm you started with, so that cannot be what stops you.

What actually stops you is the paper lost into the rounded edge of every fold. Each layer on the outside of a bend has further to travel than the layer inside it, and that difference eats real length. Britney Gallivan worked the arithmetic out in 2002 while still in high school, then folded a 1.2 km roll of toilet paper twelve times to prove it. For a square sheet folded in alternating directions her result is:

Sheet width ≥ π × thickness × 2^(3(n − 1) / 2)

Rearranged, that is the fold count this calculator reports when you give it a sheet size. It moves with both thickness and size, which is the whole point: doubling the sheet buys you about two thirds of one extra fold, so getting past seven means a much bigger sheet or much thinner paper, not more determination.

For complex origami (insects, modular designs), thinner paper of 50 to 80 GSM is essential. Wet-folding designs need stronger fiber, washi or tant, to handle moisture without tearing.