Postage Cost Calculator: 2026 USPS Letter Rates or Any Carrier’s Price Steps

How it works

USPS: price = the step whose “weight not over” limit covers the item (letters $0.82 for 1 oz, +$0.29 per extra ounce to 3.5 oz; metered letters 4¢ less; large envelopes $1.69 for 1 oz up to $5.24 at 13 oz; postcards $0.65; nonmachinable letters +$0.49) · Forever stamps = ⌈price ÷ $0.82⌉ · Any carrier: extra steps = ⌈max(0, weight − weight in base) ÷ step weight⌉, postage = base + steps × step price; or the price of the first band whose limit covers the weight

Postage is priced in weight steps: you pay for the step whose upper limit covers the item, so anything even slightly over a limit is charged at the next step. For US mail the calculator uses the USPS Notice 123 retail prices for single-piece First-Class Mail, in force since July 12, 2026: a 1 oz stamped letter is $0.82 (a Forever stamp), each additional ounce adds $0.29 up to the 3.5 oz letter limit, and metered letters are 4¢ cheaper. Heavier or larger flat mail pays large-envelope (flat) prices, from $1.69 for 1 oz to $5.24 for 13 oz; above that it is a package. Square, rigid or lumpy letters pay a $0.49 nonmachinable surcharge, and postcards are $0.65. Because Forever stamps are always worth the current 1 oz letter price, the calculator also shows how many cover the postage and by how much they overpay. For any other carrier, enter either its base price plus a price per extra weight step, or paste its weight-band table, in grams, kilograms, ounces or pounds. Size limits, extra services and package prices are not included.

Worked example

With the default step pricing ($0.82 covers the first ounce, then $0.29 per extra ounce or part of one), a 3 oz letter has 3 − 1 = 2 oz of extra weight, so 2 extra steps: 0.82 + 2 × 0.29 = $1.40, the same as the USPS stamped-letter price for over 2 oz up to 3 oz. With the USPS letter option, two Forever stamps ($1.64) cover it with $0.24 to spare, and metered it would cost $1.36. A 10 oz large envelope costs $4.32 at USPS flat prices.

Sources: USPS Notice 123: Price List (First-Class Mail letters, flats and postcards) · State of Nevada: July 2026 USPS postage increase notice (Forever stamp $0.78 → $0.82, effective July 12, 2026) · The Letter Pilot: How much are stamps in 2026? (letter rate chart)

Frequently asked questions