Calculate True Weight Calculator
Volumetric vs. Actual Shipping Weight Analysis
Imperial (Inches / Pounds)
Metric (Centimeters / Kilograms)
The longest side of the package.
Please enter a valid length > 0
The width of the package.
Please enter a valid width > 0
The vertical height of the package.
Please enter a valid height > 0
The scale weight of the package including packing materials.
Please enter a valid weight > 0
UPS/FedEx Daily Rates (139)
UPS/FedEx Retail Rates (166)
Metric Standard (5000 cm³/kg)
Metric Old Standard (6000 cm³/kg)
USPS Domestic (166 or 194)
Determines the density threshold set by the carrier.
True (Chargeable) Weight
0 lb
Based on Volumetric Weight
Actual Weight
0
Volumetric Weight
0
Total Volume
0
Formula Used: (L × W × H) / 139
A Comprehensive Guide to Calculate True Weight for Logistics
In the world of logistics and e-commerce shipping, the weight displayed on a scale is often not the weight you are billed for. To accurately budget for shipping costs, you must know how to calculate true weight, also known as "chargeable weight" or "billable weight." This metric determines the final cost of sending a package by comparing its physical heaviness against the amount of space it occupies in a truck or aircraft.
What is "Calculate True Weight"?
The term "true weight" in a shipping context refers to the greater of two values: the Gross (Actual) Weight or the Volumetric (Dimensional) Weight. Carriers developed this model to ensure they are compensated fairly for lightweight, bulky packages that take up valuable cargo space.
If you ship a large box full of pillows, its scale weight might be low, but its volume is high. If you only paid for the scale weight, the carrier would lose money on the space occupied. Therefore, you must calculate true weight to determine which metric the carrier will use for billing.
- Actual Weight: The physical weight measured on a scale.
- Volumetric Weight: A theoretical weight calculated from dimensions (Length × Width × Height) divided by a DIM factor.
- True (Chargeable) Weight: The higher of the two values above.
Calculate True Weight Formula and Explanation
To calculate true weight, you first need to determine the volumetric weight using the formula mandated by your specific carrier. The standard formulas differ slightly depending on whether you use Imperial (inches/pounds) or Metric (cm/kg) systems.
The Formulas
Imperial Formula (UPS/FedEx/DHL):
Volumetric Weight (lb) = (Length × Width × Height) / DIM Divisor
Metric Formula:
Volumetric Weight (kg) = (Length × Width × Height) / DIM Divisor
| Carrier / Service | Standard Divisor (Imperial) | Standard Divisor (Metric) | Typical Range |
|---|---|---|---|
| FedEx / UPS (Daily Rates) | 139 | 5000 | High Density |
| FedEx / UPS (Retail Rates) | 166 | 6000 | Medium Density |
| USPS (Domestic Zones) | 166 or 194 | N/A | Lower Density |
| DHL Express | 139 | 5000 | High Density |
Practical Examples: How to Calculate True Weight
Example 1: The Bulky Lightweight Package
You are shipping a large box of foam padding via UPS Ground (Daily Rates, Divisor 139).
- Dimensions: 20″ x 20″ x 20″
- Actual Weight: 10 lbs
Step 1: Calculate Volume: 20 × 20 × 20 = 8,000 cubic inches.
Step 2: Divide by Divisor: 8,000 / 139 ≈ 57.55 lbs.
Step 3: Round up: 58 lbs.
Conclusion: The Actual Weight is 10 lbs, but the Volumetric Weight is 58 lbs. The True Weight (Chargeable) is 58 lbs.
Example 2: The Small Heavy Package
You are shipping a box of metal parts via FedEx (Divisor 139).
- Dimensions: 6″ x 6″ x 6″
- Actual Weight: 15 lbs
Step 1: Calculate Volume: 6 × 6 × 6 = 216 cubic inches.
Step 2: Divide by Divisor: 216 / 139 ≈ 1.55 lbs.
Step 3: Compare: Actual (15 lbs) > Volumetric (2 lbs).
Conclusion: The True Weight is the Actual Weight: 15 lbs.
How to Use This True Weight Calculator
- Select System: Choose Imperial (lb/in) or Metric (kg/cm) based on your carrier's requirements.
- Enter Dimensions: Input the length, width, and height of your packaged item. Always measure the furthest points.
- Enter Weight: Input the gross weight from a scale.
- Select Divisor: Choose the DIM factor appropriate for your shipping service (e.g., 139 for most commercial air freight).
- Analyze Results: The calculator will instantly calculate true weight and highlight whether you are paying for size or weight.
Key Factors That Affect True Weight Results
When you calculate true weight for logistics budgeting, several factors influence the final number:
- Packaging Efficiency: Excessive void fill or oversized boxes drastically increase volumetric weight. Optimizing box size is the #1 way to reduce shipping costs.
- Carrier Divisors: A divisor of 139 results in a higher billable weight than a divisor of 166. Negotiating a higher divisor with your carrier can save thousands.
- Palletization: Shrink-wrapping boxes onto a pallet may increase the overall volume if items overhang the pallet dimensions.
- Rounding Rules: Most carriers round up to the next full inch or pound. A 12.1″ box becomes 13″, potentially bumping you into a higher price bracket.
- Irregular Shapes: Cylinders or uneven packages are usually measured as if they were in a rectangular box encompassing their widest points.
- Fuel Surcharges: These are applied to the True Weight, not just the actual weight, compounding the cost of inefficient packaging.
Frequently Asked Questions (FAQ)
What is the difference between actual weight and true weight?
Actual weight is what the scale reads. True weight (or chargeable weight) is the billing metric used by the carrier, which is the higher of the actual weight or the volumetric weight.
Why do I need to calculate true weight?
If you quote shipping based only on actual weight, you may undercharge your customers and lose margin when the carrier bills you for the volumetric size.
Does the DIM divisor change by carrier?
Yes. UPS and FedEx typically use 139 for commercial and 166 for retail. USPS uses 166. International air freight usually uses 5000 (metric) or 6000.
How can I lower my true weight?
Use the smallest possible box for your item. Switch from boxes to poly mailers for soft goods like clothing, as they have negligible volume.
Do I calculate true weight for every package?
Yes, carriers scan dimensions for every package. It is best practice to estimate this beforehand to avoid surprise bill adjustments.
Does "Calculate True Weight" apply to sea freight?
Sea freight uses a different metric called CBM (Cubic Meters). While the concept is similar (volume vs weight), the ratios are different (typically 1 CBM = 1000kg).
What if my package is a cylinder?
To calculate true weight for a cylinder, measure the diameter as both width and height, and the length as length. Essentially, treat it as a square prism.
Is true weight the same as billable weight?
Yes, these terms are used interchangeably in the logistics industry.
Related Tools and Internal Resources
Explore our suite of logistics and financial tools to optimize your supply chain:
- Freight Class Calculator – Determine the NFCMC class for LTL shipments based on density.
- Shipping Cost Estimator – Get real-time cost estimates for domestic and international zones.
- CBM Volume Calculator – Calculate cubic meters for container loading and sea freight.
- Break-Even Analysis Tool – Financial planning tool to determine profitability thresholds.
- Inventory Turnover Calculator – Analyze how fast you are selling stock to optimize warehouse space.
- Warehouse Capacity Planner – Estimate storage needs based on SKU dimensions and true weight.