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USPS USPS Package Restrictions

If you need to know how big your USPS parcel can be, we have all the numbers you need below

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What package restrictions does USPS have?

The chart below shows USPS Package Restrictions for all their major packaging options. These are the weight and dimensional limits to what USPS allows.

The Predefined Package names are drawn from the EasyPost API, so you can better reference how each Predefined Package matches up dimensionally.

Predefined Package NameDimensionsWeight
Card
  • Min: 3 ½" x 5 ½"
  • Max: 4 ¼" x 6"
Must be a flat surface
Letter
  • Min: 3 ½" x 5 ½"
  • Max: 6 ⅛" x 11 ½"
Maximum weight is 3.5 oz.
Flat
  • Min: 6 ⅛" x 11 ½"
  • Max: 12" x 15"
Maximum weight of 13 oz.
ParcelMaximum size is 108" in combined length and girth (distance around the thickest part). First-Class™ packages cannot exceed 22" x 18" x 15".Contents for Priority Mail Express, Priority Mail, or Media Mail® must weigh less than 70 lbs. First-Class™ packages must weigh less than 16 oz.
LargeParcel [1][3]Maximum size is 130" in combined length and girth (distance around the thickest part).Contents must weigh less than 70 lbs.
IrregularParcel [1][2]
  • Rolls and tubes up to 26" long.
  • This predefined parcel includes unwrapped, paper-wrapped, or sleeve-wrapped articles that are not letter-size or flat-size (e.g., catalogs, directories).
  • Articles enclosed in envelopes that are not letter-size, flat-size, or machinable parcels.
Contents must weigh less than 16 oz.
FlatRateEnvelope12 ½" x 9 ½"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateLegalEnvelope15" x 9 ½"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRatePaddedEnvelope12 ½" x 9 ½"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateGiftCardEnvelope10" x 7"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateWindowEnvelope10" x 5"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateCardboardEnvelope12 ½" x 9 ½"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateEnvelope12 ½" x 9 ½"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateBox8 ⅝" x 5 ⅜" x 1 ⅝"Contents must weigh less than 70 lbs.
MediumFlatRateBox11" x 8 ½" x 5 ½"Contents must weigh less than 70 lbs.
LargeFlatRateBox12" x 12" x 5 ½"Contents must weigh less than 70 lbs.
RegionalRateBoxA [1]
  • Option 1: 10 ⅛" x 7 ⅛" x 5"
  • Option 2: 16 ⅙" x 11 ⅙" x 2 ½"
Contents must weigh less than 15 lbs.
RegionalRateBoxB [1]
  • Option 1: 12 ¼" x 10 ½" x 5 ½"
  • Option 2: 16 ¼" x 14 ½" x 3"
Contents must weigh less than 20 lbs.
LargeFlatRateBoardGameBox
  • 23-11/16" x 11 ¾" x 3" – Inside
  • 24-1/16" x 11 ⅞" x 3 ⅛" – Outside
Contents must weigh less than 70 lbs.

[1] Not available for international shipments.
[2] Only used with Parcel Select Lightweight.
[3] Marks package for Balloon Price.

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