Measure M-weight (the weight of 1,000 sheets of paper) by providing the sheet size, basis weight, and basic size of the paper. When filling in these fields, use decimal fractions where necessary and give lengths in inches and weight in pounds.

M-Weight Calculator
 M-weight = Given Sheet Size:(length × width) length width Basis Weight: lbs. Select… Paper Grade/Basic Size:Bond (17 × 22)Book and Offset (25 × 38)Tag (24 × 36)Index (25.5 × 30.5)Vellum Bristol (22.5 × 28.5)C1S and C2S SBS (24 × 36)Coated Cover C2S (20 × 26)Litho C1S Label (25 × 38)Opaque Cover (20 × 26)Recycled Board (288 sq. in.)(Or type in values below.) Basic Size:(height × width) height width lbs.

The numerical results from this calculator are estimates only and are not guaranteed. Individual mills may use slightly different methods of calculating M-weight. Also, certain products—particularly higher-caliper SBS and recycled board—can vary dramatically in basis weight (and therefore M-weight). Lastly, actual selling M-weight may be calculated on the full width of the roll (i.e., size plus waste), thereby increasing the M-weight amount. Please call your sales representative to confirm M-weight.

## Example

Find the M-weight for a sheet of 11? × 17? book paper with a basis weight of 70 lbs.

### Formula:

 (Area of Given Sheet) × Basis Weight Area of Basic Size = Rounded Ream Weight × 2 = M-weight

### Equation:

 (11 × 17) × 70 (25 × 38) = 13.78 × 2 = 27.56

Note that in this example, the area of the given sheet size is 11 × 17 = 187 inches2 (i.e., less than 336 inches2), according to the M-weight rounding rules below, ream weight should be rounded to the nearest hundredth of a pound.

## Specifications

M-Weight Rounding Rules
Sheet Size Ream Weights
864 inches2 > Ream weight calculated to nearest pound, e.g.: 148 lbs.
336 – 864 inches2 Ream weight calculated to nearest half pound, e.g.: 148.5 lbs.
< 336 inches2 Ream weight calculated to nearest one hundredth of a pound, e.g.: 148.57 lbs.

### Terms & Definitions

Ream: 500 sheets of paper cut to a given standard size for a particular grade.

Ream Weight: The weight of 500 sheets of paper.

M-weight: The weight of 1,000 sheets of paper (or two reams).

Basis Weight: The weight of a ream, measured in pounds. (See supplemental tables below.)

Basic Size: The standard sheet size from which the basis weight of a given grade of paper is determined.

## Supplemental Tables of Approximate Basis Weights

For C1S and C2S SBS
C1S SBS C2S SBS
7 pt 105 115
8 pt 110 125
9 pt 120 135
10 pt 130 145
12 pt 150 172
14 pt 162 185
15 pt 171 190
16 pt 180 204
18 pt 198 220
20 pt 216 240
22 pt 234 260
24 pt 250 275
For Recycled Paperboard (Clay News, Clay Kraft, Clay White, Chipboard)
Caliper (inches) Basis Weight (lbs.)
.040 160
.038 152
.036 144
.034 136
.032 128
.030 120
.028 112
.026 104
.024 96
.022 88
.020 82
.018 77
.016 69
.015 65
.014 63
.013 60
.012 56