USPS First Class vs Priority Mail
The two most common USPS services a merchant uses to ship with are First Class and Priority Mail. Generally, the deciding factor in making a decision in First Class vs Priority Mail comes down to weight. If a parcel weighs less than 16 ounces, it makes the most sense to use First Class Mail. However, there are instances when the choice is not so black and white. For instance, the USPS has recently slowed First Class Mail. There are instances when one of these services will win over the other. We’ll go over a few situations where one service may win over the others.
What is USPS First Class Mail?
USPS First Class Mail is an economical way to ship parcels and thick envelopes weighing under 16 oz. The maximum allowable size for parcels are dimensions of 22″ x 18″ x 15″. Delivery usually takes 2–5 business days for parcels to reach their final destination. Letters are a little faster since they sort more quickly.
Why is it Called First Class Mail?
First Class Mail doesn’t mean the same as a first class flight. In the world of USPS, that would Priority Mail Express. First Class Mail is a class of mail used to ship letters, thick envelopes, padded envelopes, and lightweight packages. First Class Mail gets its name because is considered the top tier of mailed letters in comparison to:
- Second Class Mail: periodicals, magazines, newspapers that are printed more than 4 times a year.
- Third Class Mail: Marketing mail, flyers, mailers, etc.
- Fourth Class Mail: Media Mail (CDs, vinyl records, DVDs, books, bound print media consisting of 8 or more pages.)

Shipping T-Shirts with USPS
Shirts, especially t-shirts are a good candidate to ship with First Class Mail. They’re lightweight and durable. Try shipping in a poly mailer to cut down additional costs.
What is USPS Priority Mail?
USPS Priority Mail is the USPS’s class of mail that is their top priority to ship out. Priority Mail is a a service that lets you send parcels weighing less than 70 lbs domestically. The maximum dimensions are 108” in combined length and girth (the length of the longest side, plus the distance around the thickest part of the package). Generally, USPS Priority Mail takes 1-3 business days to reach its final destination.
Internationally, Priority Mail International gets another advantage since it typically cuts shipping time down significantly. Because of this, it is a little bit more expensive than First Class Mail.
Priority Mail is also closer to UPS and FedEx services. However, it is frequently more economical than both UPS or FedEx for packages weighing under about 10 lbs. This is generally because a USPS vehicle passes by addresses each day. Smaller parcels that can fit in a mailbox typically are economical. If the parcel’s size/weight requires the delivery driver to leave their vehicle and/or are too large to fit in their messenger bag, then the price can begin to rise quickly.

Shipping Shoes with USPS
Shoes are almost always going to ship using Priority Mail (Unless they weigh less than 16 oz). Check to see if Flat Rate options offer discounts over standard Priority Mail packaging.
Max Dimensions and Weight for USPS
USPS First Class Mail is typically used for smaller, lighter parcels—weighing under a pound—with items whose insured value is not very high. Items over a pound and/or items of higher value work better with Priority Mail.
Restriction Type | First Class Mail Max Restrictions | Priority Mail Max Restrictions |
---|---|---|
USPS First Class Mail | USPS Priority Mail | |
Max Dimensions | 108” in combined length and girth.* | 108” in combined length and girth* |
Max Weight | 15.99 oz° | 70 lbs* |
*Exceeding these maximum restrictions may result in a $100 charge applied to you by the USPS.
°4 lbs for First Class International
Insurance Coverage for USPS First Class and Priority Mail
Coverage Type | First Class Mail Coverage | Priority Mail Coverage |
---|---|---|
Domestic Coverage | N/A | $100* |
International Coverage | N/A | $200* |
A major advantage of USPS Priority Mail is that it includes coverage in the event that a parcel becomes lost or damaged in transit. First Class Mail offers no default coverage, however, both Priority Mail and First Class Mail do allow additional coverage to be purchased through the USPS or through a third-party provider such as Shipsurance.
USPS First Class vs Priority Mail Price Comparison
First Class Mail is a more economical shipping option than Priority Mail. If you would like a breakdown of the shipping rates available to you, check out these rates available to any ShipStation user through their complimentary Stamps.com account.
USPS Transit Time
Now that First Class Mail uses USPS zones when rating, it’s easier to compare transit times. Let’s take a look at the estimated delivery time it takes for different locations around the US and globally:
USPS First Class vs Priority Mail Domestic Transit Time
USPS Service | Zone 1 | Zone 3 | Zone 5 | Zone 8 |
---|---|---|---|---|
Media Mail | 2 days | 3 days | 6 days | 6-13 days |
First Class Mail | 2 days | 3 days | 3 days | 3-5 days |
Priority Mail | 1-2 day | 2 days | 2 days | 3 days |
Priority Mail Express | 1-2 days | 1-2 days | 1-2 days | 1-2 days |
USPS First Class vs Priority Mail International Transit Time
Service | Estimate Transit Time |
---|---|
First Class Mail International | No guaranteed time frame |
Priority Mail International | 6-10 days* |
Priority Express International | 3-5 days* |
What is USPS Media Mail?
Media Mail is the USPS’s more affordable, slower option for shipping CDs, vinyl records, DVDs, books, bound print media consisting of 8 or more pages. Unlike other USPS services, the USPS can inspect the package to make sure the contents are approved materials without first authorizing a search warrant.
Shipping Vinyl Records with Media Mail

Vinyl records most commonly ship with Media Mail. As do books, CDs, DVDs, and other physical media. If expedited delivery is important, consider upgrading to First Class Mail or Priority Mail (depending on the weight or insured value).
To start saving time and money on USPS services, sign up for a free ShipStation trial today!