THE TOOLKIT
Paper weight calculator.
Estimate the mass of a stack of paper from its dimensions, GSM and number of physical sheets.
The formula
Mass (g) = width (mm) × height (mm) ÷ 1,000,000 × GSM × sheets
Worked example: a ream of A4
An A4 sheet has a nominal area of 210 × 297 ÷ 1,000,000 = 0.06237 m². At 80 gsm, that is 4.9896 g per sheet. For 500 sheets, the calculated mass is 2494.8 g, or approximately 2.495 kg.
Pages and sheets are different
A sheet has two sides. A 100-page document printed on both sides normally uses 50 physical sheets, before covers or blanks. Enter 50 in the calculator for that job.
Can I use this for postage?
Use it for a paper-only estimate. Ink, covers, binding, envelopes, moisture and manufacturing tolerances change the actual mass. Weigh the finished package before buying postage.
Sources & method
- ISO 536:2019 · Paper and board: determination of grammage
- Xerox: Helpful Facts About Paper · Grammage and paper properties
- ISO 216:2007 · Nominal sheet dimensions
Dimensions use the published nominal sizes. Conversions and calculator examples are derived from those values. Calculated results are estimates for planning, not printer calibration.