Shipping Weight Limits by Carrier — Pounds and Kilograms Reference

When you're shipping a package, the weight limit isn't just one number — it depends on the carrier, the service level, the destination, and sometimes the package dimensions. Exceeding a limit by even a small margin moves your shipment into a different pricing tier or gets it rejected entirely.

This article covers weight limits for major US and international carriers in both pounds and kilograms. The Weight Converter handles any specific conversion you need.

Why Weight Limits Are in Both Units

US carriers (USPS, UPS, FedEx) use pounds for domestic shipments. International carriers and most non-US postal services use kilograms. When you're shipping internationally or comparing rates, you'll need to convert between the two.

The basic conversion: 1 lb = 0.4536 kg and 1 kg = 2.2046 lb

• 70 lbs = 31.75 kg (common maximum for domestic parcel services)
• 150 lbs = 68.04 kg (heavy freight threshold)
• 50 kg = 110.23 lbs
• 30 kg = 66.14 lbs (common international air freight limit)

USPS Weight Limits

USPS's general maximum for parcel services is 70 lbs. Above that, shipments must go through freight channels.

First-Class Package Service is capped at 13 oz — above that, packages must be shipped as Priority Mail or another parcel service. This is a common source of unexpected rate jumps: a 14-oz package that "just" goes over the 13-oz limit doubles or triples in shipping cost.

UPS Weight Limits

UPS allows up to 150 lbs per package for most services — significantly more than USPS. Packages between 70 lbs and 150 lbs require a "heavyweight" label on the outside. Above 150 lbs, packages must ship as freight.

UPS also assesses a "large package" surcharge for packages over 96 inches in combined length and girth, regardless of weight. This is the dimensional weight / "DIM weight" consideration that applies separately from actual weight.

FedEx Weight Limits

FedEx's limits parallel UPS closely — 150 lbs for standard parcel services. Like UPS, FedEx adds dimensional weight (DIM weight) calculations for larger packages, which can effectively make a lightweight large box cost more than its actual weight suggests.

International Air Freight: Standard Limits

For international shipments via postal services (not express couriers), weight limits are typically lower:

International air mail services from postal agencies are typically limited to 2 kg (4.41 lbs) for standard parcels. Above that, you typically need to use express services (DHL Express, FedEx International, UPS Worldwide) or freight.

DIM Weight: When Dimensions Override Actual Weight

Most carriers use dimensional weight (DIM weight) to price large, lightweight packages. The formula:

DIM weight = (length × width × height) ÷ DIM factor

DIM factors vary by carrier and service:

• UPS/FedEx domestic: 139 (dimensions in inches)
• USPS (for Priority Mail): 166 (dimensions in inches)
• International: varies, often 5,000 (dimensions in cm, result in kg)

If the DIM weight is greater than actual weight, the carrier charges the DIM weight rate.

Example: A 24" × 18" × 12" box weighing 8 lbs actual

• DIM weight = (24 × 18 × 12) ÷ 139 = 5,184 ÷ 139 = 37.3 lbs
• You're billed at 37.3 lbs, not 8 lbs

This is why large but light items (pillows, foam, bulky clothing) are expensive to ship — the carrier is effectively charging for the cargo space they occupy.

Overweight and Oversize Surcharges

Beyond the hard weight limits, carriers add surcharges at specific thresholds:

UPS:

• $31.45 additional handling surcharge for packages over 50 lbs
• $105+ large package surcharge for packages over 96" combined (L + 2W + 2H)
• Additional handling for certain irregular shapes

FedEx:

• Oversize surcharge for packages over 96" or 130" combined dimensions
• Additional handling for packages over 50 lbs per package in some services

USPS:

• No explicit overweight surcharge within the 70 lb limit, but size-based restrictions apply

Practical Weight Reference for Common Items

When packing, it helps to know approximate weights for common items to estimate shipping costs:

For precise weight, weigh the packed box rather than estimating. Carriers charge on the heavier of actual weight or DIM weight, so there's no benefit to underestimating.

Use the Weight Converter to convert any weight between pounds, kilograms, ounces, and grams when comparing carrier limits or completing international shipping forms.