How to Calculate USPS Delivery Time
Learn how to accurately estimate USPS delivery times. This step-by-step guide covers everything you need to know about calculating shipping times for any mail class.
Step-by-Step: Calculate USPS Delivery Time
Identify Your ZIP Codes
Find your origin ZIP code (where you're shipping from) and destination ZIP code (where it's going). You can find ZIP codes on USPS.com or Google Maps.
Determine the USPS Zone
USPS uses zones 1-9 based on distance. Zone 1 is local (same city), Zone 9 is cross-country. Our calculator determines this automatically from your ZIP codes.
Choose Your Mail Class
Select the service that fits your needs: Priority Mail Express (1-2 days), Priority Mail (1-3 days), Ground Advantage (2-5 days), First-Class Mail (1-5 days for letters), or Media Mail (2-8 days).
Check Service Standards
Each mail class has published delivery standards based on zone. For example, Priority Mail is 1 day for Zone 1, 2 days for Zones 2-3, and 3 days for Zones 4+.
Account for Cutoff Times
Mail collected after your Post Office's cutoff time (typically 4-5 PM) starts processing the next business day. Mail early for same-day processing.
Add Buffer for Variables
Consider holidays, weather, and peak seasons. During busy periods like December, add 1-2 extra days to your estimate for a realistic delivery window.
Use Our Free Calculator
Skip the manual calculation - enter your ZIP codes and get instant delivery estimates with confidence ratings.
Upcoming USPS Non-Delivery Days:
- Sun, Dec 14 - Sunday - No regular mail delivery
Ready to Calculate
Enter your origin and destination ZIP codes above, then click "Calculate Delivery Time" to see estimated arrival dates for all USPS services.
Factors That Affect USPS Delivery Time
Distance (Zones)
The farther your package travels, the longer it takes. Zone 1 (local) is fastest, Zone 9 (cross-country) is slowest.
Mail Class
Priority Mail Express is fastest (1-2 days). Priority Mail is fast (1-3 days). Ground Advantage and Media Mail are slower (2-8 days).
Time of Mailing
Mail collected after cutoff (4-5 PM) starts processing the next business day. Mail early for same-day processing.
Holidays & Weekends
USPS counts business days (Mon-Sat). Sundays and federal holidays add to delivery time. Plan around major holidays.
Weather Events
Severe weather (snowstorms, hurricanes) can delay mail. USPS prioritizes safety and may suspend delivery in affected areas.
Peak Seasons
November-December sees highest mail volume. Expect 1-2 day delays during holidays. Ship early for guaranteed arrival.
Tips for Accurate Delivery Estimates
Always use the full 5-digit ZIP code for both origin and destination
Check USPS service alerts for any current delays in your area
Add 1-2 days buffer during peak seasons (holidays, back-to-school)
Mail before your Post Office's collection cutoff time
Use Priority Mail Express if you need a guaranteed delivery date
Track your package online to see real-time progress
Frequently Asked Questions
How accurate are USPS delivery time estimates?
USPS delivery estimates are generally accurate for most shipments. However, they're not guarantees (except Priority Mail Express). Factors like weather, holidays, and mail volume can affect actual delivery. Our calculator includes confidence ratings to help set expectations.
Does USPS count weekends in delivery time?
USPS delivery times are counted in business days (Monday-Saturday). Sundays and federal holidays are not counted. For example, if you mail something on Friday with 2-day delivery, expect it Monday or Tuesday.
What time of day should I mail for fastest delivery?
Mail items as early as possible, ideally before your local Post Office's collection cutoff time (usually 4-5 PM). Items mailed late in the day may not be processed until the next business day.
How do I find the USPS zone between two ZIP codes?
Use our calculator or the official USPS Zone Chart tool. Enter your origin ZIP code to see zones for all destinations. Zone 1 is local, Zone 9 is coast-to-coast. Higher zones mean longer delivery times.