How to Calculate Dimensional Weight with a Precise Dimensional Weight Calculator
Use this dimensional weight calculator to compare actual weight and volumetric weight so you can forecast billed shipping charges, optimize packaging, and avoid surcharge surprises.
Dimensional Weight Calculator
Enter package length in the selected unit.
Enter package width in the selected unit.
Enter package height in the selected unit.
Inches (in)
Centimeters (cm)
Choose the unit used for length, width, and height.
Domestic Air: 166 in³/lb
International Air: 139 in³/lb
Metric: 5000 cm³/kg
Postal Metric: 6000 cm³/kg
Select the carrier divisor used to compute dimensional weight.
Measured package weight (lb if using inches, kg if using centimeters).
Projected carrier rate per billable pound or kilogram to preview charges.
Dimensional Weight: 0
Formula: (L × W × H) ÷ divisor
Metric
Value
Notes
Table: Dimensional weight metrics, volume, and billed weight summary.
Chart: Actual weight vs dimensional weight across divisor scenarios.
What is how to calculate dimensional weight?
How to calculate dimensional weight is the practice of converting package volume into a weight equivalent so carriers can price shipments based on the space they occupy, not just their actual mass. Businesses use how to calculate dimensional weight to estimate billed shipping charges, compare packaging options, and negotiate carrier agreements. A common misconception is that how to calculate dimensional weight only matters for air freight; in reality, major carriers apply dimensional rules across ground and postal networks when packages are bulky.
how to calculate dimensional weight Formula and Mathematical Explanation
The core equation for how to calculate dimensional weight is straightforward: multiply length, width, and height to find the cubic volume, then divide by the carrier's dimensional divisor. The divisor translates space into a billable weight unit, yielding the dimensional weight that will be compared to actual scale weight.
Step-by-step derivation:
Measure length, width, and height in the same unit.
Compute volume: L × W × H.
Apply divisor: Volume ÷ Dimensional Divisor.
Compare to actual scale weight and bill the greater value.
Variable
Meaning
Unit
Typical range
L
Package length
in or cm
6–48
W
Package width
in or cm
4–30
H
Package height
in or cm
2–24
Volume
Cubic size
in³ or cm³
500–50,000
Divisor
Carrier dimensional constant
in³/lb or cm³/kg
139–6000
Dim Weight
Volumetric chargeable mass
lb or kg
5–150
Variable reference table for how to calculate dimensional weight.
Practical Examples (Real-World Use Cases)
Example 1: Domestic air parcel
Inputs: 18 in × 14 in × 10 in, divisor 166, actual weight 12 lb. Volume equals 2,520 in³. Dimensional weight is 2,520 ÷ 166 = 15.18 lb. Because dimensional weight exceeds actual weight, the billed weight is 15.18 lb. At a $3.50 rate, projected shipping is $53.13.
Example 2: International metric shipment
Inputs: 50 cm × 40 cm × 35 cm, divisor 5000, actual weight 18 kg. Volume equals 70,000 cm³. Dimensional weight is 70,000 ÷ 5000 = 14 kg. The billed weight becomes 18 kg because actual weight is higher, showing why how to calculate dimensional weight guides packaging decisions.
How to Use This how to calculate dimensional weight Calculator
Enter length, width, and height in inches or centimeters.
Select the matching dimensional divisor used by your carrier.
Add the actual scale weight to compare against dimensional weight.
Optionally enter a rate per pound or kilogram to preview charges.
Review the highlighted dimensional weight and billed weight in real time.
Use Copy Results to share how to calculate dimensional weight outputs with your team.
The calculator displays volume, dimensional weight, billed weight, and estimated shipping cost so you can act quickly.