USPS Postage Calculator
What will it cost to mail? Check letter postage or compare package rates.
Current USPS letter and large-envelope postage
Domestic First-Class Mail letters, postcards, and large envelopes have nationwide retail prices, so ZIP codes are not required. Enter the actual weight and choose the mailpiece shape above. Package and international prices depend on the route, so those estimates use the USPS pricing API. For a breakdown of letter, postcard, and large-envelope prices, see our USPS postage-rate guide.
Rates below are effective July 12, 2026. One standard Forever stamp is worth $0.82.
Letter postage by weight
| Weight up to | Retail postage |
|---|---|
| 1 oz | $0.82 |
| 2 oz | $1.11 |
| 3 oz | $1.40 |
| 3.5 oz | $1.69 |
Letters over 3.5 ounces are not eligible for First-Class Mail letter prices. A nonmachinable letter adds $0.49.
Large envelope postage by weight
| Weight up to | Retail postage |
|---|---|
| 1 oz | $1.69 |
| 2 oz | $1.98 |
| 3 oz | $2.27 |
| 4 oz | $2.56 |
| 5 oz | $2.85 |
| 6 oz | $3.14 |
| 7 oz | $3.43 |
| 8 oz | $3.72 |
| 9 oz | $4.02 |
| 10 oz | $4.32 |
| 11 oz | $4.62 |
| 12 oz | $4.93 |
| 13 oz | $5.24 |
Choose the right mailpiece type
Postcard
Between 5 and 6 inches long, 3½ and 4¼ inches high, and 0.007 to 0.016 inch thick. A qualifying domestic postcard costs $0.65 at retail.
Letter
No more than 11½ inches long, 6⅛ inches high, or ¼ inch thick, and no heavier than 3.5 ounces. Square, rigid, clasped, or uneven letters may be nonmachinable.
Large envelope / flat
Exceeds at least one letter maximum, but is no more than 15 inches long, 12 inches high, or ¾ inch thick. It must be flexible, rectangular, uniformly thick, and no heavier than 13 ounces.
Package
Use Package when the piece is rigid, lumpy, too thick, or over the First-Class flat weight limit. Package prices depend on weight, dimensions, origin, destination, and service.
USPS Shipping Cost Calculator for Packages
Choose Package / Box above, then enter the origin and destination ZIP codes, packed weight, and dimensions. Compare USPS retail shipping costs for Ground Advantage, Priority Mail, and Priority Mail Express. Commercial discounts are not included.
USPS Ground Advantage
Usually the lowest-cost tracked package option. USPS publishes a typical delivery time of 2–5 business days.
Priority Mail
A faster package service with a typical delivery time of 2–3 business days. Delivery is not guaranteed.
Priority Mail Express
USPS's fastest domestic service, generally 1–3 days. Guarantee availability and timing depend on the route and acceptance details.
Source: USPS Notice 123 price list, First-Class Mail size and shape guidance, and domestic shipping service descriptions. Prices and delivery times are estimates; USPS makes the final classification at acceptance.