Paper Weight Calculator

Enter your paper's length, width, and grammage (GSM) — or choose a preset paper grade and size — to calculate the weight of a single sheet, a ream (500 sheets), and M-weight (1,000 sheets). Switch between inches and metric units, and get a full breakdown of paper weight in grams and pounds.

Select a standard grade to auto-fill the basic size, or choose Custom Size.

Enter length in cm (metric) or inches (imperial).

Enter width in cm (metric) or inches (imperial).

g/m²

Grams per square metre. Used in metric mode.

lbs

Basis weight in lbs. Used in imperial mode alongside a preset grade.

How many sheets do you want to weigh?

Results

Single Sheet Weight

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Single Sheet Weight (lbs)

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Ream Weight (500 sheets)

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Ream Weight (500 sheets, lbs)

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M-Weight (1,000 sheets, lbs)

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Custom Sheet Count Weight

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Sheet Area

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Paper Weight Comparison (grams)

Results Table

Frequently Asked Questions

How do you calculate the weight of a sheet of paper?

The formula is: Weight = Length × Width × GSM. Since GSM (grams per square metre) is a weight-per-area unit, you multiply the paper's area in square metres by the GSM value. For example, an A4 sheet (0.297 m × 0.210 m) at 80 GSM weighs 0.297 × 0.210 × 80 = approximately 4.99 grams.

What is GSM in paper weight?

GSM stands for grams per square metre (g/m²). It is the international standard for measuring paper weight — specifically how many grams one square metre of that paper weighs. Standard office copy paper is typically 80 GSM, while cardstock can range from 200–350 GSM.

How much does a single sheet of copy paper weigh?

A standard A4 sheet of 80 GSM copy paper weighs approximately 5 grams (0.176 oz or 0.011 lbs). This means 500 sheets (one ream) weigh about 2.5 kg (5.5 lbs), which matches the labelled ream weight you see on paper packages.

What is basis weight in paper?

Basis weight is a North American measurement that refers to the weight (in pounds) of 500 sheets (a ream) of paper cut to its 'basic size'. The basic size varies by paper grade — for Bond paper it is 17×22 inches, for Text paper it is 25×38 inches, and so on. This is why a 20 lb Bond and a 50 lb Text paper are actually the same thickness.

What is M-weight and how is it calculated?

M-weight is the weight of 1,000 sheets of paper at a given size. 'M' comes from the Latin 'mille' meaning thousand. It is calculated as: M-weight = (Sheet Length × Sheet Width × Basis Weight) / (Basic Size Area), then multiplied by 2 (since basis weight is for 500 sheets). It is commonly used in commercial printing to estimate shipping and material costs.

What is the difference between M-weight and basis weight?

Basis weight is the weight of 500 sheets at the paper's basic size, while M-weight is the weight of 1,000 sheets at the actual sheet size you are using. Basis weight is a fixed property of the paper grade, whereas M-weight changes depending on the sheet dimensions you cut or order.

What weight is standard copy paper?

Standard copy paper is typically 75–80 GSM in metric terms, or 20 lb Bond / 50 lb Text in North American basis weight terms. These two systems refer to the same paper — the difference is only in how the measurement is expressed. Heavier paper (90–120 GSM) feels noticeably thicker and is used for brochures or presentations.

Why does the same paper have different basis weights for different grades?

Each paper grade has a different 'basic size', which is the standard sheet dimension used to measure 500 sheets. Because the basic sizes differ (e.g. 17×22 for Bond vs. 25×38 for Text), the same physical paper will show different basis weight numbers depending on which grade classification is used. GSM avoids this confusion because it is a universal, area-based measurement.

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