People standing next to giant reels of paper

SI Paper Calculation Metrics

Standard methods to calculate paper and board characteristics require the use of the International System of Units (SI or SI metric units). Use our calculators below for quick results.

Apply these formulas in our calculators below

Weight in KG of a given number of sheets

How this works
Formula: (Length × Width × GSM × Sheets) ÷ 1000

Grammage of a sheet of paper (g/m²)

How this works
Formula: (Weight × 1000) ÷ (Length × Width × Sheets)

Number of sheets for a job

How this works
Formula: (Npj × Cr × (100 + %overs)) ÷ (Nps × 100)

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FAQ Section

GSM (grams per square meter) is calculated using the weight, length, and width of the paper. Use our calculator or apply the formula: GSM = (Weight in kg × 1000) / (Length in meters × Width in meters × Number of sheets).

The grammage of a sheet of paper in G/M2 is calculated by: Grammage = (W × 1000) / (L × Swd × Ns) where W = weight in kg, L = length in meters, Swd = width in meters, Ns = number of sheets. 

Calculating grammage ensures that the paper meets specific quality, strength, and suitability requirements for printing, packaging, or converting. 

The internationally recognized standard is ISO 536:2019, which defines the method for determining grammage (mass per unit area) of paper and board. 

Use the formula: Weight (kg) = L × Swd × GSM × Ns / 1000, where L = length in meters, Swd = width in meters, GSM = grams per square meter, and Ns = number of sheets. 

GSM measures the mass per unit area (grams per square meter), while weight is the total mass of a specific quantity of sheets or a roll. 

Yes! Our online calculators simplify the process and reduce errors in determining paper characteristics like grammage and weight.