Dimensional Weight Calculator
Calculate volumetric weight using carrier-specific divisors. Multi-piece support with unit conversion and rounding options.
Enter Dimensions
| Length (cm) | Width (cm) | Height (cm) | Qty | Weight (kg) | |
|---|---|---|---|---|---|
How Dimensional Weight Works
Carriers use dimensional weight (DIM weight) to price shipments based on package size, not just physical weight. This prevents shippers from paying low rates for large, lightweight packages.
The formula is simple:
The divisor varies by carrier. Express services typically use 5000 cm³/kg (or 139 in³/lb), while economy services may use 6000 cm³/kg (or 166 in³/lb).
Worked Example
Example: Shipping 2 boxes via DHL Express
Box 1: 40cm × 30cm × 20cm, Qty: 2, Actual weight: 3kg each
- Volume = 40 × 30 × 20 = 24,000 cm³ per box
- Dimensional weight = 24,000 ÷ 5000 = 4.8 kg per box
- Total for 2 boxes = 4.8 × 2 = 9.6 kg dimensional
- Actual weight for 2 boxes = 3 × 2 = 6 kg
- Chargeable = max(9.6, 6) = 9.6 kg
Box 2: 60cm × 40cm × 40cm, Qty: 1, Actual weight: 15kg
- Volume = 60 × 40 × 40 = 96,000 cm³
- Dimensional weight = 96,000 ÷ 5000 = 19.2 kg
- Chargeable = max(19.2, 15) = 19.2 kg
Total chargeable weight: 9.6 + 19.2 = 28.8 kg
With DHL's 0.5kg rounding: 10 + 19.5 = 29.5 kg
Common Mistakes to Avoid
- 1.Using the wrong divisor
Divisors vary by carrier and service level. Express is usually 5000, economy is often 6000.
- 2.Forgetting to round
Many carriers round up to 0.5kg or 1kg. Check your rate card.
- 3.Mixing units
Use metric (cm/kg with divisor 5000) or imperial (in/lb with divisor 139) consistently.
What is Dimensional Weight?
Dimensional weight (also called volumetric weight or DIM weight) is a pricing technique used by shipping carriers to charge based on package size rather than just actual weight. It ensures carriers are compensated for the cargo space used by large, lightweight packages. The concept applies to parcel shipping (DHL, FedEx, UPS, USPS) — freight shipping uses CBM instead.
The two standard formulas are:
Dimensional Weight by Carrier
| Carrier | Metric Divisor (cm³ → kg) | Imperial Divisor (in³ → lb) | Notes |
|---|---|---|---|
| DHL Express | 5,000 | 139 | Rounds up to nearest 0.5 kg |
| FedEx Express | 5,000 | 139 | — |
| FedEx Ground | 6,000 | 166 | — |
| UPS | 5,000 | 139 | — |
| USPS Priority Mail | 5,000 | 166 | Ground Advantage uses 166 |
| Australia Post | 5,000 | — | — |
| Canada Post | 5,000 | — | — |
| La Poste / Colissimo | 5,000 | — | — |
| Royal Mail | 5,000 | — | — |
FedEx Express
Metric Divisor: 5,000 · Imperial Divisor: 139
FedEx Ground
Metric Divisor: 6,000 · Imperial Divisor: 166
UPS
Metric Divisor: 5,000 · Imperial Divisor: 139
Australia Post
Metric Divisor: 5,000
Canada Post
Metric Divisor: 5,000
La Poste / Colissimo
Metric Divisor: 5,000
Royal Mail
Metric Divisor: 5,000
Divisors may vary by account type, service level, and negotiated rates. Always confirm with your carrier.
Practical Tips for Managing Dimensional Weight
- 1.Right-size your packaging
Choose the smallest box that safely fits your items. Even 2-3 cm of extra space per dimension adds up.
- 2.Compare carrier divisors
Economy services often use 6000 instead of 5000, giving lower dimensional weight for the same package.
- 3.Consider vacuum packing
For soft goods like clothing, vacuum sealing can reduce package dimensions by 50% or more.
- 4.Document everything
Keep dimension and weight records to verify carrier invoices and catch billing errors.
Frequently Asked Questions
What is dimensional weight?
Dimensional weight (also called volumetric weight or DIM weight) is a pricing technique used by carriers. It calculates weight based on package dimensions rather than actual weight, using the formula: Volume ÷ Divisor. Carriers charge the greater of actual weight or dimensional weight.
What divisor should I use?
The divisor depends on your carrier and service. Common metric divisors are 5000 (express services) and 6000 (economy). Imperial divisors are typically 139 or 166. Always confirm with your carrier as rates can vary by account.
How do I calculate dimensional weight for multiple packages?
Calculate the dimensional weight for each package separately, then sum them. Use our multi-piece calculator above—add a row for each package type and specify the quantity.
What is chargeable weight?
Chargeable weight (or billed weight) is the weight used to calculate shipping cost. It's the greater of actual weight or dimensional weight. Some carriers round up to the nearest 0.5kg or 1kg.
Why is my package charged by dimensional weight?
If your package is large but light (like a pillow or empty box), its dimensional weight exceeds its actual weight. Carriers charge the higher value to reflect the space your package occupies in their vehicles.
Is dimensional weight the same as volumetric weight?
Yes, they are identical. 'Dimensional weight' is more common in the US, while 'volumetric weight' is used internationally. The calculation is the same.
Why does dimensional weight exist?
Carriers have limited space in vehicles, planes, and ships. Large, lightweight packages take up valuable cargo room. Dimensional weight ensures carriers are compensated for the space occupied, not just the weight carried.
Can I negotiate a different divisor with my carrier?
Yes, businesses with regular shipping volumes can often negotiate better divisors through their carrier account manager. Higher volume shippers typically receive more favorable rates.