Accurately determine Volumetric Weight vs. Actual Weight for shipping estimates
Metric (cm / kg)
Imperial (in / lb)
Select the units used by your local post office.
Please enter a valid length.
Please enter a valid width.
Please enter a valid height.
The weight shown on a physical scale.
Please enter a valid weight.
Standard: 5000 (Metric) or 139 (Imperial). Check with your carrier.
Cost per kg or lb charged by the post office.
Billable Weight
1.80
kg
The post office will charge based on this weight.
Volumetric Weight
1.80
Actual Weight
1.50
Estimated Cost
9.00
Comparison: Actual vs. Volumetric Weight
Metric
Value
Calculation Note
What is a Post Office Parcel Weight Calculator?
A post office parcel weight calculator is an essential tool for shippers, eCommerce business owners, and individuals looking to estimate shipping costs accurately. Unlike simple scales that measure how heavy an object is, this calculator determines the "Billable Weight" by comparing the Actual Weight against the Volumetric (Dimensional) Weight.
Postal services and courier companies (like USPS, FedEx, DHL, and UPS) use this method to ensure they are paid fairly for the space a package occupies in a truck or aircraft. If you ship a large box full of feathers, it takes up significant space despite being light. The post office parcel weight calculator helps you predict whether you will be charged for the size or the weight of your package.
Post Office Parcel Weight Calculator Formula
The core calculation relies on the concept of Dimensional Weight (DIM Weight). The formula varies slightly depending on whether you use the metric or imperial system.
Result: Since 5 kg > 1.2 kg, the post office charges you for 5 kg (Actual Weight).
How to Use This Post Office Parcel Weight Calculator
Select Your System: Choose between Metric (cm/kg) or Imperial (in/lb) based on your location.
Measure Dimensions: Measure the length, width, and height of your packaged box. Always round up to the nearest whole number if your carrier requires it.
Weigh the Package: Place your package on a scale to get the Actual Weight.
Check the Divisor: The default is 5000 for metric and 139 for imperial, but check with your specific post office or carrier (e.g., DHL often uses 5000, FedEx domestic might use 139).
Analyze Results: Look at the "Billable Weight" to see what you will likely pay for.
Key Factors That Affect Parcel Weight Results
Carrier Divisors: Different carriers use different divisors (e.g., 4000, 5000, or 6000). A lower divisor results in a higher billable weight.
Packaging Efficiency: Using a box that is too large for the item increases volumetric weight unnecessarily. This is a major cost factor in logistics.
Rounding Rules: Most post offices round dimensions to the nearest cm/inch and weights to the next 0.5kg or lb.
Irregular Shapes: For cylinders or non-rectangular items, carriers usually calculate based on the smallest rectangular box that could enclose the item.
Zone Distances: While this calculator focuses on weight, the final cost is heavily influenced by the shipping zone (distance).
Surcharges: Items exceeding certain lengths or weights may incur "Over Maximum Limits" surcharges regardless of the calculated weight.
Frequently Asked Questions (FAQ)
Why is my billable weight higher than the scale weight?
This happens when your package is light but bulky. Carriers charge for the space occupied (volumetric weight) rather than just the physical mass.
What is the standard DIM divisor for international shipping?
The most common international standard is 5000 (cm³/kg). However, some express services use 6000, while domestic US services often use 139 or 166 (in³/lb).
Does this calculator apply to envelopes?
Generally, no. Flat envelopes are usually charged by actual weight or flat rates. This post office parcel weight calculator is designed for boxes and parcels.
How can I reduce my shipping costs?
Use the smallest box possible for your item. If you are shipping soft goods (like clothes), use a poly mailer instead of a box to reduce volume.
Do I include the pallet weight?
Yes, if you are shipping freight, the weight of the pallet and all packaging materials must be included in the Actual Weight.
What if my package is a cylinder?
Measure the diameter as both the width and height, and the length as the length. Treat it as a rectangular box for calculation purposes.
Is the "Cost per Unit" accurate?
It is an estimate. Actual rates depend on zones, fuel surcharges, and specific carrier contracts. Always verify with the official post office price list.
Can I use this for air freight?
Yes, air freight relies heavily on volumetric weight, often using a divisor of 6000. You can adjust the "DIM Factor" input to 6000 to calculate this.