A 500-gram cushion in a 40 × 30 × 20 cm box ships as 4.8 kg. Couriers charge by the space a parcel takes as much as by what it weighs, and volumetric (dimensional) weight is how they measure it: length × width × height in centimetres divided by a carrier-specific divisor. This calculator computes volumetric weight for Delhivery, Blue Dart, DTDC, Xpressbees, Ecom Express, Shadowfax, DHL/FedEx and air cargo, compares it with actual weight to find the chargeable weight, and shows what a smaller box would save.
The formula and the divisors
Volumetric weight (kg) = L × W × H (cm) ÷ divisor.
| Carrier / mode | Divisor |
|---|---|
| Delhivery, Ekart, DTDC, Xpressbees, most aggregators (surface) | 5000 |
| Blue Dart, DHL, FedEx domestic | 4000 |
| Ecom Express, Shadowfax | 4500 |
| International air cargo | 6000 |
| Amazon/Flipkart fulfilment fees (typical) | 5000 |
Chargeable weight = the higher of actual and volumetric, rounded up to the carrier's slab (usually 0.5 kg). The 40 × 30 × 20 cm box at divisor 5000 is 4.8 kg → billed as 5 kg; at Blue Dart's 4000 it is 6 kg.
Estimating the price, not just the weight
Courier pricing in India is chargeable weight × your rate, and the rate is the part no calculator can know for you: it depends on your contract, the zone (local, regional, metro, rest of India, North-East and J&K), the mode (surface or air) and whether the shipment is prepaid or COD. Delhivery, Blue Dart, DTDC, Xpressbees and Ecom all publish slab rates per 500 g by zone for walk-in customers, and give aggregator or contract customers something lower.
So: take the first slab rate from your own rate card or your aggregator dashboard, enter it here, and the tool prices the parcel at the correct chargeable weight. That is the number that is usually wrong when a seller is surprised by an invoice — not the rate, but the weight the rate was applied to.
How to use the calculator
- Enter the parcel's length, width and height in cm and its actual weight.
- Pick the carrier divisor (or enter a custom one from your rate card).
- Read the volumetric weight, the chargeable weight after rounding, and — if you enter a rate per kg or per 500 g — the estimated freight.
- Try smaller dimensions; the tool shows the saving per parcel and per 100 parcels.
- Use the multi-parcel mode for a B2B consignment: total chargeable weight for several boxes.
Why box size is the cheapest optimisation
Cutting the cushion's box to 32 × 26 × 12 cm gives 2 kg volumetric — a 3 kg reduction, or roughly ₹60–120 per parcel on domestic surface rates. Over 500 parcels a month that is ₹30,000–60,000. Steps that pay for themselves in a week:
- Stock three or four box sizes and pick the tightest fit; avoid one "universal" carton.
- Use vacuum bags for soft goods, corrugated mailers for flat items, and poly bags where damage risk is low.
- Measure the packed parcel, not the product; filler and folded flaps add centimetres.
- Round dimensions honestly — carriers re-measure at the hub and bill the difference plus a penalty.
The full marketplace fee stack, and how chargeable weight interacts with commission and closing fees, is in Pricing for Amazon, Flipkart and Meesho; the seller pricing workflow uses this calculator's result directly.
Air, international and B2B
Air cargo uses a 6000 divisor (1 cbm = 167 kg) and the same higher-of rule; ocean LCL freight is charged per cubic metre instead. For domestic B2B on surface transport (part-truck load), rates are per kg with a volumetric equivalent of about 1 cbm = 250–350 kg depending on the transporter — ask for the "CFT rate". Put the chargeable weight on the shipping label and the delivery challan so there is no argument at the hub.
Related tools
- Shipping label generator — prints the chargeable weight on the label.
- Seller pricing workflow — shipping cost inside the listing price.
- Fuel expense calculator — the cost of delivering it yourself.
- Contribution margin — does the order still make money after freight?
- Delivery challan — for non-sale shipments.