Guide ยท Weights and volume
Lbs to kg on shipping documents: conversion, rounding and declaring units
One pound is exactly 0.45359237 kg, so multiply pounds by that factor. Convert the total rather than each carton, round once at the end, and write the unit in every weight column. Shortcuts such as dividing by 2.2 drift by kilograms on a full container.
The conversion and where it drifts
The international avoirdupois pound is defined as exactly 0.45359237 kg. So kg = lb x 0.45359237, and lb = kg x 2.2046226. A 55 lb carton is 24.948 kg. Most international carriers and customs systems work in kilograms, even when the factory weighs in pounds, so the document needs a kg figure and a stated unit.
Rounding is where totals drift. 120 cartons at 55 lb is 6,600 lb, or 2,993.71 kg. Rounding each carton to 24.95 kg first gives 2,994.00 kg (+0.29 kg). Dividing 6,600 by 2.2 gives 3,000 kg (+6.29 kg), and multiplying by 0.45 gives 2,970 kg (-23.71 kg). A total that is off by kilograms will not tie to a total that was converted exactly. See gross weight vs net weight for what the totals mean.
General information, not customs or legal advice. Which unit a document must use depends on the country and the form; the destination's rules and your broker decide.
Convert a list in six steps
Find the unit
Read the column headers and totals line for lb, lbs or pounds. If no unit is written, ask the supplier instead of assuming.
Total first, then convert
For a row, multiply pounds per carton by the cartons, then by 0.45359237.
Keep precision to the end
Hold at least three decimals while you work, then round each reported figure once.
Convert the declared totals the same way
If the list declares totals in lbs, convert them with the same factor before comparing them with your converted rows.
Write the unit
"G.W. (kg)" in the header and kg on the totals row. Say on the document if the figures were converted from pounds.
Do the same for dimensions
Inches become centimetres at 2.54 before CBM is worked out; see CBM calculation for cartons.
Conversion factors
Exact or rounded as shown, with a worked example for each.
| Unit | Equals | Example |
|---|---|---|
| 1 lb | 0.45359237 kg | 55 lb = 24.948 kg |
| 1 kg | 2.2046226 lb | 25 kg = 55.116 lb |
| 1 oz | 28.349523 g | 16 oz = 453.59 g |
| 1 short ton (US, 2,000 lb) | 907.18474 kg | 1.5 short tons = 1,360.78 kg |
| 1 long ton (UK, 2,240 lb) | 1,016.0469 kg | 2 long tons = 2,032.09 kg |
| 1 tonne (metric) | 1,000 kg | 2.6 tonnes = 2,600 kg |
Converting the declared totals as well
A list that declares its totals in pounds has to be compared with converted rows on the same footing. Rows that add up to 2,993.71 kg set against a declared total of 6,600 (still in pounds) show a variance of more than half the weight, although nothing on the list is wrong. Convert the declared total with the same factor and the variance disappears.
Expect a few hundredths of a kilogram of rounding after conversion. A small tolerance, such as 0.05 kg, separates that from a real difference.
What goes wrong
- Shortcut factors. 2.2 and 0.45 are close, but the error grows with the weight. The 6,600 lb example above is out by 6.29 kg or 23.71 kg.
- Rounding every carton. A small per-carton rounding multiplies by the carton count.
- Mixed units in one list. Some rows in lbs and the rest in kg. The sum means nothing, and the reader cannot see which rows were converted.
- Ton misread. A short ton, a long ton and a metric tonne differ by up to about 12 percent. Ask which one the supplier means.
- No unit at all. A list that says 55 with no unit. If kg is assumed and the supplier meant lbs, the shipment looks about 2.2 times heavier than it is. Packing list errors that cause customs holds lists the other usual mismatches.
How CargoSheet helps
CargoSheet converts weights written in lbs to kg with 0.45359237, converts the list's declared totals the same way, and marks the affected rows "Converted from lbs". If no weight unit is written anywhere in the file, it assumes kg and says so in the notes, so you can check with the supplier. Try the packing list to Excel converter. Free: 1 file per day, up to 10 pages, no account. Files over 10 pages are converted up to page 10 on the free allowance; a page code converts the whole file, up to 150 pages. See pricing.
Questions
- How do you convert lbs to kg?
- Multiply pounds by 0.45359237. 55 lb x 0.45359237 = 24.948 kg. To go back, divide kilograms by the same factor or multiply by 2.2046226.
- Is it acceptable to divide pounds by 2.2?
- Only as a rough check. It overstates the weight by about 0.2 percent. On a 6,600 lb shipment that is 6.29 kg, enough to disagree with a total that was converted exactly.
- Should I round each carton or the total?
- The total. Rounding every carton first lets the error grow with the number of cartons. Convert, add, then round once to the precision the document uses.
- How many decimals should kilograms have on a shipping document?
- Two decimals are common, but follow the form's field length and your carrier's instructions, and use the same precision on every document for the shipment.
- Do customs authorities require kilograms?
- Many work in kilograms and expect the unit to be stated, but practice differs by country, and some forms use pounds. Ask your broker which unit the entry needs.
- What if the packing list does not state the unit?
- Ask the supplier. Reading pounds as kilograms overstates the weight about 2.2 times, and reading kilograms as pounds understates it by the same factor. If you must proceed, record your assumption in writing.
Check a packing list against its own totals
Free: 1 file per day, up to 10 pages, no account.