Paper Weight & Print Job Weight Calculator
Convert a paper stock’s basis weight or GSM using its basic sheet size, then estimate the M-weight and paper-only shipping weight for the production sheets in your job.
Total job weight (lb)160
- Total job weight (kg)
- 72.57
- M-weight
- 160
- Weight per sheet (grams)
- 72.57
- Equivalent GSM
- 118.41
- Equivalent basis weight
- 80
Basis weight is for 500 basic-size sheets; this result uses a 950.00 in² basic sheet.
Job weight includes paper only and excludes pallets, packaging, ink, and binding materials.
How to use this calculator
- Choose whether the stock specification is a U.S. basis weight or grammage in GSM.
- Enter the paper weight and select the stock class that matches the supplier’s basic sheet size.
- Use Custom basic size only when the stock class is not listed and the mill has supplied its basic dimensions.
- Enter the actual production-sheet dimensions, which can differ from the basic sheet size.
- Enter every sheet to be printed or shipped, including spoilage when it belongs in the weight estimate.
How paper and job weight are calculated
U.S. basis weight is not a direct measure of one sheet’s mass. It is the pounds in 500 sheets at a stock class’s basic size. Text paper uses a 25 × 38 inch basic sheet, while cover uses 20 × 26 inches. The same number of pounds therefore describes a different mass per area for each class.
The calculator first finds the basic-sheet area Ab in square inches. For an entered basis weight B, grammage is:
G = B × 1,406.1308 ÷ Ab
For an entered grammage G, the equivalent basis weight is:
B = G × Ab ÷ 1,406.1308
The factor accounts for 500 sheets, pounds converted to grams, and inches converted to square metres. It is why 80 lb text and 80 lb cover are not comparable descriptions of paper mass. The selected stock class supplies Ab; custom dimensions should come from the mill specification.
Production-sheet and job calculations
The basic size is only used for the basis-weight conversion. Actual job weight uses the production sheet you enter. Its area is A = W × H × 0.00064516 square metres, where W and H are inches. One sheet weighs S = G × A grams. M-weight, the pounds in 1,000 production-size sheets, is M = S × 1,000 ÷ 453.59237. Total paper mass is Tkg = S × N ÷ 1,000 kilograms or Tlb = S × N ÷ 453.59237 pounds.
Sheet area and sheet count scale the total directly. Changing the stock class can also change the result substantially when you enter basis weight, because it changes the basic area. When you enter GSM, stock class changes the displayed equivalent basis weight, while the production-sheet mass stays the same.
What this estimate leaves out
This is a theoretical paper-only mass. Moisture, coatings, manufacturing tolerance, and scale accuracy can change actual weight. GSM and basis weight describe mass per area, not caliper, stiffness, opacity, or press suitability. Confirm unusual classifications and supplier specifications before buying stock or rating freight, and add pallets, cartons, wrapping, ink, and binding materials separately.
Worked example
For 80 lb text stock, the basic size is 25 × 38 inches, or 950 square inches. Its equivalent grammage is 80 × 1,406.1308 ÷ 950 = 118.41 GSM. If the production sheet is also 25 × 38 inches, one sheet has an area of 0.612902 m² and weighs 118.41 × 0.612902 = 72.57 g.
For 1,000 sheets, the M-weight is 160 lb and the total paper weight is 72.57 kg, or 160 lb. A different production sheet changes the per-sheet and job weight even when the stock’s basis weight stays the same.
Common questions
Why does 80 lb text paper differ from 80 lb cover paper?
Each name refers to 500 sheets at a different basic size. Text uses a 25 × 38 inch basic sheet and cover uses 20 × 26 inches, so 80 pounds is spread over much more area for text paper. As a result, 80 lb text is about 118 GSM while 80 lb cover is about 216 GSM.
What is a paper basic size?
A basic size is the traditional untrimmed sheet size used to define a U.S. paper class’s basis weight. A basis weight is the pounds in 500 sheets of that basic size, not the pounds in 500 sheets of every size cut from it. The supplier or mill specification is the best source for an unusual grade.
How do I convert basis weight to GSM?
Multiply the basis weight by 1,406.1308 and divide by the basic-sheet area in square inches. The basic area must match the stock class, so there is no single pounds-to-GSM conversion factor. Use the inverse formula, GSM times basic area divided by 1,406.1308, to convert back.
What does M-weight mean in commercial printing?
M-weight is the weight in pounds of 1,000 sheets at the actual production-sheet size. It helps estimate handling, shipping, and paper usage without first multiplying every sheet count. It is distinct from basis weight, which uses 500 sheets at the stock class’s basic size.
Does GSM measure paper thickness?
No. GSM is mass per unit area, while thickness is caliper. Two sheets with the same GSM can differ in thickness, stiffness, opacity, surface finish, and press behavior because of fibre, coating, bulk, and manufacturing choices.
Should spoilage sheets be included in the sheet count?
Include them when you want the paper requirement or expected shipping and handling weight for the whole run. Leave them out when you only need the mass of delivered sheets. The calculator does not add a spoilage allowance by itself, so the entered count controls that choice.