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Package Girth Calculator

Length plus girth, and whether it triggers a surcharge.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Commonly 130 for oversize and 165 maximum, in inches.

Length plus girth

74.0 in

within standard limits

Longest side30.0 in
Girth — 2 × (w + h)44.0 in
Threshold130 in
Headroom56.0 in

How the Package Girth Calculator works

Girth measures around the parcel rather than along it, and carriers use length plus girth to catch long thin packages that dimensional weight alone would miss. Crossing the threshold triggers oversize surcharges that frequently exceed the base shipping rate.

Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price — check the platform's current fee schedule before you price a product against it. This is not tax or business advice.

Frequently asked questions

How is girth calculated?

2 × (width + height), using the two smaller dimensions. Length plus girth is then the longest side plus that figure. A 30 × 12 × 10 inch box has a girth of 44 inches and a combined measurement of 74.

What are the usual limits?

Most major carriers apply oversize charges above 130 inches combined and refuse parcels above 165. Postal services generally have lower limits. The exact thresholds vary by carrier and service, so check before designing packaging around them.

What does an oversize surcharge cost?

Often £50-100 or more per parcel, and it can exceed the base rate. Some carriers also apply a minimum billable weight to oversize parcels regardless of what they actually weigh.

How do I avoid oversize charges?

Redesign packaging to keep the longest dimension down, split into two parcels where that is cheaper than one surcharged one, or move to LTL freight for genuinely large items — freight is often cheaper than surcharged parcel.

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