CalcThai
calcthai.com · Parcel Volumetric Weight Calculator
General & conversion
Parcel Volumetric Weight Calculator
Work out a box's volumetric weight from length × width × height ÷ the carrier's divisor, compare it with actual weight and find the chargeable weight with step rounding and an estimated shipping cost.
Ask about this page
The AI assistant answers only questions about the calculator on this page.
Work out a box's volumetric weight from length × width × height ÷ the carrier's divisor, compare it with actual weight and find the chargeable weight with step rounding and an estimated shipping cost.
How it works
Volumetric weight (kg) = length × width × height (cm) ÷ divisor. Many carriers use 5,000 or 6,000. Chargeable weight is the larger of actual and volumetric weight, rounded up to the carrier's step. Cost = total chargeable weight × rate per kg.
Example: a 40 × 30 × 20 cm box is 24,000 cm³; ÷ 5,000 = 4.8 kg, above the 3 kg actual weight, so with 1 kg steps it is charged as 5 kg. With a 6,000 divisor it is 4.0 kg.
Divisors, rounding steps, size limits and price tables differ by carrier and service, and some price by weight band or zone instead of a flat per-kg rate. Check current terms before shipping and measure the longest points, including bulges.
Frequently asked questions
Why is a light box charged more?
Large boxes take up vehicle space, so carriers charge volumetric weight when it exceeds actual weight. A snug box can cut the cost.
Which divisor should I use?
Use the figure your carrier or service publishes. If unsure, try both 5,000 and 6,000 to see the possible range.
Can several boxes be combined?
This tool calculates each box and adds them, which matches separate parcels. Some freight services price a whole consignment together.
Sources
Method last verified 21 Sep 2026