Key takeaways
- Couriers and Canada Post international parcels charge by the higher of real weight and volumetric weight
- Volumetric weight for DHL, FedEx and Canada Post Xpresspost/International Parcel: L × W × H in cm ÷ 5,000
- Canada Post Small Packet and Tracked Packet ignore volumetric weight but stop at 2 kg
- A smaller box can cut your price a lot when your parcel is light but bulky
- Sea cargo boxes are priced per box, so fill them well
How carriers decide what to charge
Every carrier works out two weights and charges for the higher one:
- Real weight: what the packed box weighs on a scale.
- Volumetric (dimensional) weight: the space the box takes, turned into kilograms.
For international parcels, Canada Post, DHL Express and FedEx all use the same formula:
Length × Width × Height (in cm) ÷ 5,000 = volumetric weight in kg
Canada Post applies this to Priority, Xpresspost, Expedited and its U.S. and international services, but not to Tracked Packet and Small Packet. Those two have a 2 kg maximum instead. Canada Post uses a different divisor (6,000) for its domestic Regular Parcel service, which does not apply to parcels going abroad.
How this calculator works
- It finds your volumetric weight with the 5,000 divisor and compares it with the real weight.
- It checks the Canada Post limits: 2 kg for Small Packet and Tracked Packet, and the maximum for Xpresspost and International Parcel. For India, Canada Post lists 20 kg. For other countries the general maximum in Canada Post’s June 2026 chart is 30 kg, but a country can set less.
- If you enter a courier price per kg, it multiplies it by the chargeable weight.
- If you enter a Canada Post price or a sea cargo box price, it shows the cost per real kilo so you can compare.
- It tells you how much smaller your box would need to be for the volumetric weight to match the real weight.
We do not show carrier prices by default, because they change often and depend on your postal code, fuel surcharges and the exact service. Get live quotes from each carrier’s website and enter them here.
Worked example
You pack 8 kg of clothes into a 50 × 40 × 40 cm box.
- Volume: 50 × 40 × 40 = 80,000 cm³.
- Volumetric weight: 80,000 ÷ 5,000 = 16 kg.
- A courier charges you for 16 kg, not 8 kg: twice the real weight.
If you move the same 8 kg into a 40 × 30 × 30 cm box (36,000 cm³), the volumetric weight is 7.2 kg. Now the courier charges for the real weight, 8 kg. That can halve the price. Soft items like clothes compress well, so a smaller box often pays off.
Comparing post, courier and sea cargo
Use the result like this:
- Under 2 kg: Canada Post Small Packet or Tracked Packet ignore box size, so they are often cheapest for light gifts. See the India guide for coverage limits.
- 2 kg to 20 or 30 kg: compare Canada Post Xpresspost or International Parcel with courier quotes on the same chargeable weight.
- Large boxes of personal goods: a sea cargo box at a flat price can be much cheaper per kilo, but takes weeks. Read our balikbayan box guide.
Also add costs at the other end: duty and tax, and any delivery or collection fee. India has no duty-free gift allowance for post and courier parcels.
Before you ship
- Check our banned items checklist. Canada Post does not take lithium batteries outside Canada and the U.S.
- Fill in the customs declaration with a real description and value.
- Keep your receipt, tracking number and photos of the contents.
- Ask if sending money would be cheaper: see sending money home.