Convert GSM to LBS or LBS to GSM for paper weight, and estimate single sheet or total paper weight from GSM, sheet size, and count.

Basis weight is the mass of 500 sheets at the selected basic sheet size, not the mass of one finished sheet.

Paper basis pounds, pounds per 1,000 ft² and total pounds describe different quantities. Choose the task and its area basis.

Confirm the supplier’s basic size; it may differ from the purchased sheet size.

GSM to LBS Conversion Formula

The fixed-area formula below converts GSM to pounds per 1,000 square feet. For paper basis pounds instead, use: basis lb = GSM × basic sheet area (m²) × 500 / 453.59237. The calculator offers both conventions and actual sheet or stack mass.

lb per 1000 ft² = GSM × (92.90304) / (453.59237) ≈ GSM × 0.2048161436

Variables:

  • LBS is the paper weight in pounds per 1000 square feet
  • GSM is the paper weight in grams per square meter
GSM to Pounds per 1000 ft² Conversion Table
GSM (g/m²) lb per 1000 ft² (lb/1000 ft²)
5010.241
6012.289
7014.337
7515.361
8016.385
9018.433
10020.482
11022.530
12024.578
13026.626
14028.674
15030.722
17034.819
18036.867
20040.963
22045.060
25051.204
30061.445
35071.686
40081.926
* Rounded to 3 decimals using lb/1000 ft² = GSM × 92.90304 / 453.59237. Inverse: 1 lb/1000 ft² ≈ 4.882428 g/m².

What is GSM and LBS in Paper Weight?

GSM is mass in grams per square meter. A value labeled only “lb” needs an area basis: US paper basis weight usually means the mass of 500 basic-size sheets for the paper grade, while lb per 1,000 ft² uses a fixed area. These quantities differ from the total mass of a purchased sheet or stack.

How to Calculate GSM to LBS?

The following steps outline how to convert GSM to LBS.

  1. First, determine the GSM value of the paper.
  2. For pounds per 1,000 ft², multiply GSM by 92.90304 / 453.59237. For paper basis pounds, choose the grade’s basic sheet size and use the 500-sheet formula above.
  3. Finally, calculate the LBS value.
  4. After inserting the GSM value and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following variable as an example problem to test your knowledge.

At 150 g/m², the fixed-area value is approximately 30.722 lb per 1,000 ft². The same material is approximately 101.341 lb text basis (25 × 38 inches, 500 sheets), so the conventions must be labeled.