The mailing toolkit
USPS mail tools
From the right address to the right postage.
A few useful tools for whatever you’re mailing.
USPS Delivery Time Estimator
Estimate how long mail takes between any two U.S. states for First-Class and Priority Mail.
Estimate delivery timeZIP+4 Lookup Tool
Enter a full address to get the 9-digit ZIP+4 code and USPS-standardized format using USPS address data.
Find a ZIP+4 codePostage & envelopes
Work out the size, stamps, and cost.
USPS Mailing Cost Calculator
Calculate letter postage and compare USPS package estimates using weight, dimensions, and destination.
Envelope Size Finder
Find an envelope for your paper or card, see how it fits, and compare common envelope dimensions.
Certified Mail Fee Calculator
Calculate total USPS Certified Mail costs including postage, service fees, Return Receipt, and Restricted Delivery options.
Addresses & ZIP codes
Check the details before you send.
USPS Address Validator
Verify and correct U.S. addresses against USPS address data. Get ZIP+4 codes and standardized formatting.
ZIP Code Validator & City/State Lookup
Check if a ZIP code is valid and see its primary city and state using USPS city/state data.
USPS-Style Address Standardizer
Clean up capitalization, street abbreviations, and ZIP formatting. Formatting only—not address verification.
Tracking & updates
See where your mail is and what the status means.