Dimensional Weight Calculator — Air Freight DIM Weight

Dimensional weight is the freight industry's way of charging for the space a shipment occupies, not just its physical weight. If you don't account for it, your freight cost estimate will be wrong — sometimes dramatically. This calculator instantly shows you whether actual weight or dimensional weight applies to your shipment.

The Dimensional Weight Formula

For air freight and express couriers:

Dimensional Weight (kg) = (L cm × W cm × H cm) ÷ 5,000
Chargeable Weight = max(Actual Weight kg, Dimensional Weight kg)

For sea freight (CBM/W/M):

Volume (CBM) = (L cm × W cm × H cm) ÷ 1,000,000
Chargeable = max(Volume CBM, Weight in metric tons)

Break-Even Density: When Does Dim Weight Apply?

The critical density threshold is 200 kg/m³ (for a 5,000 divisor):

• Products denser than 200 kg/m³: Actual weight governs — you pay for what it weighs
• Products lighter than 200 kg/m³: Dimensional weight governs — you pay for the space

Worked Example: 3 Products, Same Actual Weight

All three cartons weigh 5 kg actual. Carton size 50×40×30 cm.

Dimensional weight = (50 × 40 × 30) ÷ 5,000 = 60,000 ÷ 5,000 = 12 kg
Chargeable weight = max(5, 12) = 12 kg

Compressing a carton from 50×40×30 to 40×30×20 saves $42 per carton in freight — that's $4,200 per 100 cartons on a China-to-US air shipment.

Carrier Dimensional Weight Divisors

Packaging Optimization to Reduce Dim Weight

1. Reduce dead air — fill gaps with paper or air pillows that compress flat
2. Increase units per carton — doubling units per carton halves the per-unit dim weight
3. Flat-pack design — furniture and soft goods that ship flat save 60–80% on dim weight
4. Polybag vs box — clothes in polybags instead of boxes reduce CBM by 30–50%
5. Vacuum sealing — pillows, comforters, and foam products compress to 20% of their volume