Our postage label provider maintains a convenient list of the various package type restrictions, copied below:

Predefined Package Name Dimensions Weight
Card
  • Min: 3 1/2“ x 5 1/2"
  • Max: 4 1/4” x 6”
Must be a flat surface
Letter
  • Min: 3 1/2” x 5 1/2”
  • Max: 6 1/8” x 11 1/2”
Maximum weight is 3.5 oz.
Flat
  • Min: 6 1/8” x 11 1/2”
  • Max: 12 x 15”
Maximum weight of 13 oz.
Parcel Maximum size is 108" in combined length and girth (distance around the thickest part). Contents for Priority Mail Express, Priority Mail, or Media Mail® must weigh less than 70 lbs. First-ClassTM packages must weigh less than 13 oz.
LargeParcel Maximum size is 130" in combined length and width (distance around the thickest part). Contents must weigh less than 70 lbs.
IrregularParcel
  • Rolls and tubes up to 26 inches 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 70 lbs.
FlatRateEnvelope 12-1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateLegalEnvelope 15" x 9 1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRatePaddedEnvelope 12 1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateGiftCardEnvelope 10" x 7"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateWindowEnvelope 10" x 5"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
FlatRateCardboardEnvelope 12 1/2" x 9-1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateEnvelope 12 1/2" x 9 1/2"
  • Contents must weigh less than 70 lbs.
  • International Weight limit: 4 lbs.
SmallFlatRateBox 8 5/8" x 5 3/8" x 1 5/8" Contents must weigh less than 70 lbs.
MediumFlatRateBox 11 x 8 1/2 x 5 1/2 Contents must weigh less than 70 lbs.
LargeFlatRateBox 12 x 12 x 5 1/2 Contents must weigh less than 70 lbs.
RegionalRateBoxA
  • Option 1: 10 1/8 x 7 1/8 x 5
  • Option 2: 16 1/6 x 11 1/6 x 2 1/2
Contents must weigh less than 15 lbs.
RegionalRateBoxB
  • Option 1: 12 1/4 x 10 1/2 x 5 1/2
  • Option 2: 16 1/4 x 14 1/2 x 3
Contents must weigh less than 20 lbs.
RegionalRateBoxC 15 x 12 x 12 Contents must weigh less than 25 lbs.
LargeFlatRateBoardGameBox
  • 23-11/16" x 11-3/4" x 3" – Inside
  • 24-1/16" x 11-7/8" x 3-1/8" – Outside
Contents must weigh less than 70 lbs.

How does Cratejoy calculate shipping?