Shipping calculator

USPS Dimensional Weight Calculator

This USPS calculator reflects the July 12, 2026 move from divisor 166 to 139 for listed domestic parcel services. It also checks the one-cubic-foot threshold.

Rules updated for 2026

Live calculator

Calculate dimensional & billable weight

Enter finished outside dimensions. Results update with every change.

CALCULATES LOCALLY · NO UPLOAD

Length in Width in Height in Actual weight lb

Dimensions Weight Carrier / method

DIM divisor Editable. The unit follows the selected preset. Apply carrier-style whole-unit rounding

FORMULA

DIM Weight = Length × Width × Height ÷ DIM Divisor

Billable weight is the greater applicable actual or dimensional weight.

ESTIMATED BILLABLE WEIGHT-

Dimensional weight-

Actual weight-

Cubic size-

Difference-

Billing basis-

Enter package measurements to calculate.

VOLUME-

DIVISOR UNITin³/lb

Method

How this calculation works

The 2026 rule applies to listed services including Priority Mail Express, Priority Mail, Ground Advantage, and Parcel Select. Verify the DMM for your mailpiece. ParcelCal runs the calculation in your browser; no package or shipment information is uploaded.

FORMULA

USPS DIM weight = Rounded cubic inches ÷ 139 (when volume exceeds 1,728 in³)

The 2026 rule applies to listed services including Priority Mail Express, Priority Mail, Ground Advantage, and Parcel Select. Verify the DMM for your mailpiece.

Worked example

USPS threshold and new divisor

1.20 × 14 × 10 = 2,800 in³, above 1 ft³
2.2,800 ÷ 139 = 20.14 lb
3.Round up: 21 lb DIM weight

Before July 12, 2026, divisor 166 would have produced 17 lb after rounding; the updated divisor produces 21 lb.