USPS Length + Girth Calculator
USPS size limits
USPS enforces thresholds that affect what you pay and whether your package ships. The calculator above flags each one automatically.
- Up to 84 inches: Standard rates.
- 84 – 108 inches: Between 84 and 108 inches, USPS applies oversized pricing — the package is rated as if it weighed 20 lbs minimum (or 50 lbs for some services).
- Over 108 inches: Over 108 inches, USPS will not accept the package for retail mailing.
Maximum single side: 108 in. Maximum weight: 70 lb. Always verify against the current USPS rate guide before shipping high-value items.
How USPS measures girth
USPS uses the standard girth formula:
girth = 2 × (width + height)
length + girth = length + 2 × (width + height)
Worked example. A 50 × 20 × 20 inch box has girth (20 + 20) × 2 = 80 inches, and length + girth = 130 inches.
USPS measures girth as the distance around the thickest part. For tubes, that's the circumference; for boxes, 2 × (W + H).
USPS vs other carriers
If your package exceeds USPS limits, here's how it compares:
| Carrier | Max L + G | Compare |
|---|---|---|
| UPS Ground | 165 in / 419 cm | UPS Ground → |
| FedEx Ground | 165 in / 419 cm | FedEx Ground → |
| DHL Express | 157 in / 399 cm | DHL Express → |
| Royal Mail | 118 in / 300 cm | Royal Mail → |
| Canada Post | 118 in / 300 cm | Canada Post → |
| Australia Post | 55 in / 140 cm | Australia Post → |
Frequently asked
What is the maximum girth allowed by USPS?
USPS allows up to 108 inches (274 cm) combined length plus girth. Between 84 and 108 inches, USPS applies oversized pricing — the package is rated as if it weighed 20 lbs minimum (or 50 lbs for some services).
How is USPS girth calculated?
Girth equals 2 × (width + height), using the two smaller dimensions. Add the longest side for length + girth.
What happens if my package exceeds the limit?
Over 108 inches, USPS will not accept the package for retail mailing.
Does USPS measure tubes differently?
USPS measures girth as the distance around the thickest part. For tubes, that's the circumference; for boxes, 2 × (W + H).