USPS Mail Class Guide

The USPS Postal Service® has many different mail classes ranging from regular First Class Mail® letter delivery to overnight expedited services such as Priority Mail Express®. Here is a breakdown of each USPS service to help you choose the right mail class for your mailpiece.

Mail Class Speed Stamps.com
Starting Price
Cheapest
Tracking Option
Restrictions
First Class
Mail Letter
1–3 days* $0.46** $3.35 Certified Mail™ Shape and weight
restrictions
First Class
Mail Flat
1–3 days* $0.98 $3.35 Certified Mail Shape and weight
restrictions
First Class
Package Service
1–3 days* $2.67** Free USPS Tracking** Shape and weight
restrictions
Priority Mail® 1–3 days* $5.95 and up** Free USPS Tracking** N/A
Priority Mail Express® 1–2 days* $21.18 and up** Free USPS Tracking** N/A
Retail Ground (formerly Standard Post®) 2–9 days* Not Available Free USPS Tracking** N/A
Media Mail® 2–9 days* $2.63 Free USPS Tracking** Content
restrictions apply
Swipe right to see entire table *The USPS does not guarantee delivery times for any service except Priority Mail Express.
** Prices listed are discounted rates available for online postage vendors such as Stamps.com.
First Class Mail has many size and weight restrictions. Get more information on USPS First Class Mail Characteristics.

First Class Mail

Pros:

  • Low-cost and fast – great value for
    light-weight packages.
  • Pricing not affected by distance.
  • No fuel or home delivery surcharges.

Cons:

  • Maximum weight is only 13 oz.
  • First Class Mail letters and flats are not eligible for USPS Tracking.

When to use First Class Mail: If your mail or package is less than 13 oz. and you do not need overnight delivery, use First Class Mail.


Priority Mail

Pros:

  • 1–3 day delivery nationwide for packages.
  • A variety of flat-rate options to simplify shipping.
  • USPS provides free packaging.
  • Free USPS Tracking.
  • Moderate pricing.
  • Packages can weigh up to 70 lbs.
  • No fuel or home delivery surcharges.

Cons:

  • More expensive than other lower cost USPS mail classes.
  • Less expensive options, such as First Class Mail, may be equally as fast.

When to use Priority Mail: If you are shipping more than 13 oz., Priority Mail is a great shipping option for fast delivery at a low price — the USPS even offers free packaging!


Priority Mail Express

Pros:

  • Overnight delivery 365 days/year.
  • USPS provides free packaging.
  • The only USPS method with guaranteed delivery dates.
  • Packages can weigh up to 70 lbs.
  • No fuel or home delivery surcharges.

Cons:

  • Most expensive USPS Mail Class.

When to use Priority Mail Express: If you need your package to be delivered as fast as possible, regardless of price, use Priority Mail Express. If delivery can wait a day or two, First Class Mail and Priority Mail are much cheaper options.


Media Mail

Pros:

  • Cheapest shipping service for anything over 13 oz.
  • Pricing is based on weight, not distance.
  • Packages can weigh up to 70 lbs.
  • No fuel or home delivery surcharges.

Cons:

  • Much slower than most other mail classes.
  • Content must be books, sound recordings, recorded video tapes, printed music, or recorded computer-readable media (such as CDs, DVDs, and diskettes).

When to use Media Mail: Perfect for media such as books or DVDs when lower shipping rates are more important than delivery speed.


Standard Post

Pros:

  • Inexpensive pricing based only on weight (not distance).
  • Packages can weigh up to 70 lbs.
  • No fuel or home delivery surcharges.

Cons:

  • Much slower than most other mail classes.

When to use Standard Post: Use Standard Post when your content does not qualify for Media Mail and lower shipping rates are more important than speed.


How to send mail for each mail class

With Stamps.com, you can print postage for any USPS mail class without a trip to the Post Office. Customers also have access to discounted postage rates for Priority Mail and Priority Mail Express, SCAN form printing, and the ability to import order data from ecommerce marketplaces such as eBay®, Amazon® and other popular shopping carts.


Digital Scale Included* with Sign-up

Every new customer account starts with:

  • Free 5 lb. Digital Scale*, connects via USB
  • 4-week trial
  • $5 in USPS postage to use in trial period
  • Free Supplies Kit including postage labels
  • Additional $10 postage coupons to use after trial
  • Only $15.99 per month, including the first month if you stay past the 4-week trial
    *pay only S&H fee