Volumetric Weight Calculator (Shipping from Japan)
Couriers don’t just charge for what your parcel weighs — they charge for the space it takes up. Enter your box dimensions and actual weight to see the chargeable weight your proxy or forwarder will bill, and whether your shipment is "light for its size."
Calculate chargeable weight
Enter the three dimensions and a weight above 0.
Formula: volumetric weight (kg) = L × W × H (cm) ÷ divisor. Chargeable weight = the greater of actual and volumetric weight. Carriers usually round up to the next 0.5 kg, so the real bill can be a little higher.
Why a light box can cost more than a heavy one
A 60 × 40 × 40 cm box of foam-packed anime figures might weigh only 3 kg on the scale, but its volumetric weight at ÷5000 is 19.2 kg — so you pay for ~19 kg, not 3. Meanwhile a dense 5 kg box of books that measures 30 × 20 × 15 cm has a volumetric weight of just 1.8 kg, so it is billed on its actual 5 kg. Knowing which side you’re on tells you whether to repack tighter, split the order, or pick a different service.
This is also why proxy and forwarding quotes for big-but-light items (Gunpla, plush, futons, boxed electronics) come in higher than people expect. Run the numbers here before you commit to a courier.
FAQ
What is volumetric (dimensional) weight?
It is a weight calculated from a parcel’s size rather than what it weighs on a scale: volumetric weight (kg) = length × width × height (cm) ÷ a carrier divisor (usually 5000). Carriers use it so a large but light box — a Gunpla kit, a futon, foam-packed figures — still pays for the space it occupies on the plane.
Which weight will I actually be charged?
The chargeable weight is the greater of your parcel’s actual (scale) weight and its volumetric weight. If the volumetric weight is higher, your box is "light for its size" and you pay on volume. Most carriers then round the chargeable weight up to the next 0.5 kg (and sometimes 1.0 kg), so treat the result here as a floor.
Why is the divisor 5000?
For centimetres and kilograms, 5000 is the IATA standard used by DHL, FedEx and UPS. A few economy and postal services use 6000, which is slightly more generous for bulky items. Always confirm the divisor in your carrier’s or proxy service’s current rate card — this tool lets you switch between 5000 and 6000.
Does Japan Post / EMS use volumetric weight?
EMS and other Japan Post services are generally billed on actual weight (with maximum size limits) rather than a volumetric divisor, while commercial couriers (DHL, FedEx, UPS) apply volumetric weight. When a proxy quotes you a courier price for a large box, the volumetric figure is usually why it is higher than the scale weight.
Estimates only. Divisors, rounding rules and size limits vary by carrier and service tier — always confirm against your proxy service’s or carrier’s current rate card. This tool does not account for oversize surcharges or maximum-dimension limits.