Why Volumetric Weight Matters — The ÷6000 Rule
Airlines charge on chargeable weight — the higher of actual weight or volumetric weight. This exists because light, bulky cargo takes up space that could otherwise carry denser freight. If you ship a box of pillows, the airline isn't going to charge you $3 because it weighs 3 kg.
Chargeable Weight = MAX(Actual Weight, Volumetric Weight)
Total Cost = Chargeable Weight × Rate per kg × (1 + Fuel Surcharge %)
Example: A box measuring 60 × 40 × 30 cm weighs 3 kg actual. Volumetric weight = 60 × 40 × 30 ÷ 6,000 = 12 kg. You are billed for 12 kg, not 3 kg. At $5/kg, that's $60 instead of $15 — a 4× difference.
Enter your dimensions above and the calculator will show you both weights side by side so you know which one your carrier will use before you get the invoice.
Actual Weight vs Volumetric Weight — Which Will You Pay?
The rule is simple: pay whichever is higher. In practice:
- Dense cargo (machinery, metals, liquids) — actual weight usually drives the charge. Volumetric weight is lower.
- Light/bulky cargo (furniture, foam, clothing) — volumetric weight usually drives the charge. The box takes more space than it weighs.
- Electronics and packaged goods — can go either way. Always calculate both before quoting a client or placing a PO.
÷6000 vs ÷5000 — Which Divisor Applies?
The IATA industry standard divisor for airlines and most air freight forwarders is ÷6,000. However, express couriers — DHL Express, FedEx, UPS — typically use ÷5,000, which produces a higher volumetric weight and therefore a higher charge for bulky shipments.
This calculator uses ÷6,000. If your carrier uses ÷5,000, your actual chargeable weight will be 20% higher than shown. Always check your rate sheet or ask your agent which divisor applies to your booking.
How to Reduce Your Air Freight Bill
- Pack tighter. Reduce empty space inside cartons — smaller outer dimensions directly reduce volumetric weight.
- Consolidate shipments. Fewer, more efficiently packed cartons often produce better density than many small boxes.
- Check if it's worth dense packing. If actual weight is already close to volumetric, adding denser inner packing can bring parity — you won't pay more but won't pay less either.
- Compare airlines and forwarders. Rates vary significantly by carrier, trade lane, and volume commitment. Get multiple quotes.
- Consider sea freight for non-urgent cargo. For anything that can wait 3–5 weeks, ocean freight is typically 10–15× cheaper per kg.
How to Use This Calculator
- Enter cargo dimensions and select the unit (cm is default for ÷6000 calculation).
- Enter quantity and actual weight per piece.
- Enter the rate per kg your forwarder or airline quoted.
- Enter the fuel surcharge percentage (typically 15–25% for major carriers).
- See chargeable weight, volumetric weight, actual weight, and total estimated cost — all at once.
Frequently Asked Questions
What is the volumetric weight formula for air freight?
Volumetric weight (kg) = L (cm) × W (cm) × H (cm) ÷ 6,000. This is the IATA standard used by most airlines and freight forwarders. If your volumetric weight is higher than your actual weight, the airline charges you on volumetric weight.
What divisor do DHL, FedEx, and UPS use?
DHL Express, FedEx, and UPS typically use ÷5,000 for express courier shipments — not ÷6,000. This produces a higher volumetric weight for the same dimensions, making bulky, lightweight cargo more expensive via couriers than via traditional air freight. Always confirm the divisor in your rate agreement before calculating.
How can I reduce my air freight cost?
Pack cartons tighter to reduce volumetric weight, consolidate multiple small shipments into fewer larger ones, and compare rates across multiple airlines and forwarders. For non-urgent cargo, switching from air to sea freight typically saves 80–90% on freight cost.
What is the difference between air freight and courier?
Air freight (cargo) uses airline belly space or freighters via a freight forwarder, typically airport-to-airport with separate customs brokerage. Couriers (DHL, FedEx, UPS) offer integrated door-to-door service including customs clearance. Couriers use ÷5,000 divisor and are faster for small shipments; air freight is more cost-effective for 50 kg and above.
How do I calculate air freight cost per kg?
Cost = Chargeable Weight × Rate per kg × (1 + Fuel Surcharge %). Where chargeable weight = MAX(actual weight, volumetric weight). Example: 50 kg actual, 45 kg volumetric, rate $4.50/kg, 20% fuel surcharge. Cost = 50 × $4.50 × 1.20 = $270.
More Air and Freight Tools
For a standalone chargeable weight calculation without cost, use the chargeable weight calculator. To measure your cargo volume before calculating air freight, start with the CBM calculator. If your shipment is going by sea instead, compare LCL and FCL options with the LCL vs FCL calculator.