How Many Stamps Do You Need for 3 Pieces of Paper?
Demystify mail postage. Learn the key factors—from weight to envelope type—that determine the correct number of stamps for your domestic letters.
Sending mail in the United States requires appropriate postage to ensure delivery. Postage, typically stamps, covers the cost of processing and transporting mail. The amount of postage needed for a domestic letter depends primarily on its weight and, in some cases, its dimensions or characteristics. Understanding these factors helps ensure your mail reaches its destination without delay or additional charges.
Standard First-Class Mail Basics
First-Class Mail is the most common domestic letter service. A standard First-Class Mail letter must be a rectangular envelope, weigh no more than 3.5 ounces, and adhere to size limits generally between 3.5 inches by 5 inches and 6 1/8 inches by 11 1/2 inches, with a thickness of up to 1/4 inch. For a standard letter weighing up to 1 ounce, a single Forever stamp is typically sufficient.
Forever stamps are a convenient option because they are always valid for the current First-Class Mail 1-ounce letter rate, regardless of future price increases. A Forever stamp purchased years ago still covers the current 1-ounce postage rate of $0.78 as of July 13, 2025.
Calculating Postage for Multiple Pages
The number of stamps for a letter, especially with multiple pages, depends on its total weight. Each additional ounce, or fraction thereof, beyond the first ounce requires supplemental postage, which is $0.29 as of July 13, 2025.
When mailing three pieces of standard printer paper (typically 20 lb bond paper) with a common letter-sized envelope, the combined weight usually remains well within the initial 1-ounce limit. A single sheet of 20 lb bond paper weighs about 4.5 to 5 grams, and a standard envelope weighs 5 to 7 grams. Three sheets and an envelope total roughly 18.5 to 22 grams, well under 1 ounce (28.35 grams). Consequently, a single Forever stamp typically covers the postage for three pieces of standard paper. If using heavier paper stock or including additional items, it is advisable to weigh the mailpiece to determine if additional postage is necessary.
Other Factors Affecting Postage
Beyond weight, certain characteristics of a mailpiece can influence the required postage, even if it weighs under the 1-ounce limit. The United States Postal Service (USPS) applies a “non-machinable surcharge” to letters that cannot be processed efficiently by automated equipment. This surcharge, which is $0.46 as of July 13, 2025, is added if a letter is square, unusually shaped, lumpy, rigid, or contains clasps, string, or buttons. Letters with an aspect ratio (length divided by height) outside specific ranges or those with contents creating an uneven thickness may also incur this fee.
Mailpieces exceeding the dimensions of a standard letter are classified as “large envelopes” or “flats,” which have different postage rates. These larger items, generally over 6 1/8 inches high, 11 1/2 inches long, or 1/4 inch thick, start at a higher base rate, currently $1.63 for the first ounce as of July 13, 2025. While they can weigh up to 13 ounces, their size automatically places them in a different pricing category, regardless of how few pages they contain.