How many sheets are in a ream of paper?

A ream of paper is 500 sheets. This is a fixed standard for modern copy and printer paper, so any "ream" you buy — 20 lb copy paper, coloured paper, or letterhead — contains 500 sheets unless the pack explicitly says otherwise. Older or specialty definitions of a ream were 480 or 516 sheets, but for everyday office paper it is 500.

A standard case (carton) of paper holds 10 reams, which is 5,000 sheets. That is why a case is the cheapest way to buy paper per sheet — the same paper costs noticeably less per sheet by the case than as a single ream, and it stores indefinitely in a dry place. Some heavier or specialty papers come 4 or 8 reams to a case, so check the count.

It depends entirely on how much you print. For a typical home that prints a few pages a day, one 500-sheet ream can last several months to a year. A small office printing dozens of pages a day may go through a ream in a week or two. Because paper stores well, buying a case up front and drawing it down is usually cheaper than repeated single-ream trips.

Across the office paper we track, cost per sheet runs from about $0.011 to a $0.014 median — so a 500-sheet ream works out to roughly $5.70 to $6.97. The number to compare is cost per sheet (pack price ÷ sheet count), not the price of the ream or case: buying by the case almost always wins, and premium bright-white or heavier paper costs more per sheet for the same printing job.