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

Q: What is the weight of a ream of paper?

When the manufacturer weighs the paper its not 500 8.5” x 11” size sheets, its 500 17” x 22” size sheets which are 4x the size of 8.5”x11”. Some quick math and that works out to a weight of 5 pounds for a ream of 8.5” x 11” size paper.

Paper weight can be confusing. There are two ways that paper weight is measured and stated. The United States measures paper weight in pounds, whereas it is standard to measure in grams per square meter outside of the US.

Índice Show

FORMULA AND EXAMPLE
FORMULA AND EXAMPLE
FORMULA AND EXAMPLE
FORMULA AND EXAMPLE
FORMULA AND EXAMPLE
FORMULA AND EXAMPLE
$ PER MSI/MSF
FORMULA AND EXAMPLE
$ PER LINEAR FT/YD
FORMULA AND EXAMPLE
What is the weight of a ream of paper?
How much do 1000 pieces of paper weigh?
How do you convert ream to KG?
Why does a ream of paper say 20 pounds?

Paper weight in the US is stated in lbs. and is determined by weighing 500 sheets (a ream) in the basis size of a particular paper. For example, the basis size (or in other words, the master sheet size) of our Watercolor papers is 22”x30”. If you place 500 master sheets of our 400 Series Watercolor paper in the 22”x30” size on a scale, it should weigh approximately 140lbs.

The part that can get confusing when weighing paper in pounds is that not all paper types have the same basis size. For example, drawing papers have a basis size of 24”x36”, versus watercolor papers which have a basis size of 22”x30”. 500 Sheets of 400 Series Drawing paper (24”x 36”) weighs 80lbs. If you look at our 500 Series Aquarius II Watercolor paper, it also is listed as 80lbs, but the basis size of Aquarius II is 22”x30”, not 24”x36”, so it’s not exactly an apples-to-apples comparison.

On the other hand, weighing paper in grams per square meter does give you a clean, apples-to-apples comparison. Measuring paper weight in grams per square meter (commonly referred to as gsm or g/m2) is literally taking the weight in grams of 1 square meter of paper. So even though both Drawing and Aquarius II are listed as the same weight in pounds (80lbs), the master size sheets being weighed are not the same (again the drawing paper basis size is 24” x 36” and the watercolor paper basis size is 22” x 30”). When these two papers have the same size (one square meter), we see that the Watercolor paper actually weighs more than the drawing paper (130gsm vs. 170gsm).

COMMON PAPER WEIGHTS

This chart shows various papers and their common basis sizes & weights. A papers weight does not necessarily reflect quality. It is usually a reflection of intended use. Watercolor papers are heavier weight because of their need to hold a lot of water, versus drawing & sketch papers which are intended for dry media.

You will find the weight of our papers stated in both lbs. and gsm on our packaging, in our catalogs and on our website.

M-WEIGHT

FORMULA AND EXAMPLE

(Sheet dimen.) X Basis wt. / (Area of basic size) = Rounded ream wt. X 2 = M-WeightThe M-weight of a sheet of 11×17” book paper with a basis weight of 70 lbs. is: (11×17) X 70 / (25×38) = 13.78 X 2 = 27.56

The area of the given sheet size is 11 x 17 = 187 inches2. Since this is less than 336 inches2, ream weight should be rounded to the nearest hundredth of a pound.

BASIS WT.

FORMULA AND EXAMPLE

GSM X Basic Size / 1406.5 = Basis Weight (lbs.)The basis weight in lbs. for a ream of 25 x 38” book paper that weighs 67.3 grams per square meter (GSM) is: 67.3 X (25 x 38) / 1406.5 = 45 lbs.

GSM

FORMULA AND EXAMPLE

Basis Weight (lbs.) X 1406.5 / Basis size = GSMThe weight in grams per square meter (GSM) for a ream of 25 x 38” book paper that has a basis weight of 45 lbs. is: 45 x 1406.5 / (25 x 38) = 67 GSM

PPI

FORMULA AND EXAMPLE

2 / Caliper = Pages per Inch (PPI)The pages per inch (PPI) for 100# gloss coated cover with an average caliper of .0095 inches per sheet is: 2 / .0095 = 211 PPI

LINEAR FT.

FORMULA AND EXAMPLE

(Roll Weight × [Area of Basic Size]) × 500 ÷ (Basis Weight × Roll Width) × 12 = Linear Feet ÷ 3 = Linear YardsThe linear footage and yardage for a 25×38” roll of basis 50# offset paper that is 26′′ wide and weighs 100 lbs. is: [(100 × [25×38]) × 500] ÷ [(50×26) × 12] = 3,045 Linear Feet ÷ 3 = 1,015 Linear Yards

MSI/MSF

FORMULA AND EXAMPLE

Weight of Roll ÷ (Basis Weight ÷ [Area of Basic Size]) × 2 = MSI ÷ 144 = MSFThe MSI and MSF for a 900-pound roll of 80# book paper is 900 ÷ (80 ÷ [25×38]) × 2 = 5,344 MSI ÷ 144 = 37.111 MSF

$ PER MSI/MSF

FORMULA AND EXAMPLE

(Basis Weight ÷ Area of Basic Size) × 2 × Price per Pound = Price per MSI × 144 = Price per MSFThe price per MSI and MSF for a roll of 70# book paper priced at $.58 per pound is [70 ÷ (25×38)] × 2 × 0.58 = $0.0855 price per MSI × 144 = $12.3120 price per MSF

$ PER LINEAR FT/YD

FORMULA AND EXAMPLE

(MSF Price × Roll Width) ÷ 12,000 = $ per linear foot
(MSF Price × Roll Width) ÷ 4,000 = $ per linear yardThe price per linear foot for a roll of paper with a width of 26.75′′ and an MSF price of $31.50 is ($31.50 × 26.75) ÷ 12,000 = $0.0702. The price per linear yard for a roll of paper with a width of 26.75′′ and an MSF price of $31.50 is ($31.50 × 26.75) ÷ 4,000 = $0.2107

What is the weight of a ream of paper?

When the manufacturer weighs the paper it's not 500 8.5” x 11” size sheets, it's 500 17” x 22” size sheets which are 4x the size of 8.5”x11”. Some quick math and that works out to a weight of 5 pounds for a ream of 8.5” x 11” size paper.

How much do 1000 pieces of paper weigh?

Standard office copy paper weighs approximately 10.0 lbs per 1000 sheets.

How do you convert ream to KG?

Ream Weight Paperboard in Reels 1500 x 100 x 80 x 0.0001 = 120 kg.

Why does a ream of paper say 20 pounds?

Each group of the grade of paper is assigned a standard size that all weights are referred to. The basics of this standard are as follows: Bond has a standard size of 17 x 22" and this is the size that is measured for 500 sheets. If 500 sheets of this size weigh 20lbs., then the paper is classified as a 20lb.