Kg to Lbs Converter (kilograms to pounds and back)

This kg to lbs converter turns kilograms into pounds and pounds into kilograms. Type a weight, pick a direction, and it shows the answer with the same weight written as decimal pounds, pounds and ounces, stone and pounds, grams and ounces.

The link between the two units is a definition, not a measurement. Since 1959 the pound has been exactly 0.45359237 kilograms in the United States, the United Kingdom, Canada, Australia, New Zealand and South Africa. So a kilogram is 1 ÷ 0.45359237 pounds, a number that never ends but that the converter carries to 34 significant digits before rounding it for you.

The quick rule most people use, "multiply by 2.2", is close but always a little low. On a 100 kg weight it misses by almost half a pound. The converter uses the exact factor, so the difference never builds up.

1. Type the weight. Decimals are fine.
2. Choose Kilograms to pounds or Pounds to kilograms.
3. Read the headline, given to four decimal places. The cards show decimal pounds and kilograms to six places, the pounds and ounces split, the stone and pounds split, grams and ounces.

Presets load 15 kg, 70 kg and 150 lb. Below the converter, two tables cover 0.5 kg to 150 kg and 1 lb to 300 lb, each downloadable as CSV.

1. Choose the starting unit. The direction says whether your number is kilograms or pounds. A negative weight is read as zero.

1. Convert through the kilogram. The pound is stored as exactly 0.45359237 kg. Kilograms to pounds divides by that number; pounds to kilograms multiplies by it.

1. Split into pounds and ounces. The pound total is cut at the decimal point; the whole part is pounds and the remainder times 16 is ounces, rounded to two places. If the ounces round up to 16, a pound is carried.

1. Split into stone and pounds. The same weight is expressed in stone, 14 pounds each. The whole part is stone and the remainder times 14 is pounds, rounded to two places, with the same carry rule.

1. Round for display only. The arithmetic runs at 34 significant digits. The headline is rounded to four places, pounds and kilograms on the cards to six, grams to two and ounces to four, half up with trailing zeros dropped.

The default, 1 kilogram to pounds:

1. Pounds: 1 ÷ 0.45359237 = 2.2046 lb in the headline, 2.204623 lb on the card.
2. Pounds and ounces: 2 lb 3.27 oz.
3. Grams: 1,000. Ounces: 35.274.

A 15 kg suitcase: 15 ÷ 0.45359237 = 33.0693 lb, or 33 lb 1.11 oz. A bag that weighs 33 lb on a home scale is just under 15 kg.

A 70 kg body weight: 154.3236 lb, which is 154 lb 5.18 oz, or 11 st 0.32 lb in stone.

150 lb to kilograms: 150 × 0.45359237 = 68.0389 kg, and in stone 10 st 10 lb.

Each figure is taken from the converter's reference tables. The 23 kg row comes to just over 50 lb.

A kilogram is 2.204623 pounds to six places. The full value has no last digit, because 0.45359237 does not divide evenly into 1. For everyday use, 2.2046 is plenty; for a recipe, 2.2 is usually close enough; for a shipping invoice or a weight limit, use the converter's figure.

In the United Kingdom and Ireland body weight is often given in stone and pounds. A stone is exactly 14 pounds. The converter shows that split for every weight, so 70 kg reads as 11 st 0.32 lb and 200 lb as 14 st 4 lb. The stones to pounds converter on this site handles that pair on its own if you need it.

• Pounds and ounces typed together. There is one input. Convert 154 lb 5 oz as 154.3125 lb (5 divided by 16 is 0.3125), or convert the pounds and add the ounces separately.
• Troy pounds. Precious metals use a troy pound, which is lighter. It is not used here.
• Scale accuracy and clothing. A bathroom scale reading is only as good as the scale, and a few hundred grams of clothes or a full water bottle will move it more than any rounding here.
• Mass versus force. Kilograms and pounds here are units of mass. Pound-force and kilogram-force, used in engineering, are different units.

• Using 2.2. It is fine for a rough idea, but it always runs low and the gap grows with the weight.
• Dividing when you should multiply. Pounds are the smaller unit, so the pound figure is always the bigger number. If your answer in pounds is smaller than the kilograms, the direction is backwards.
• Reading 50.7 lb as 50 lb 7 oz. The decimal is a fraction of a pound. 50.70632 lb is 50 lb 11.3 oz.
• Half-kilo shortcuts. "A pound is half a kilo" overstates the pound; 0.5 kg is 1.102311 lb.

• NIST Handbook 44, Appendix C, General Tables of Units of Measurement: the avoirdupois pound and ounce. nist.gov/pml/owm/nist-handbook-44-current-edition
• National Bureau of Standards Miscellaneous Publication 233, Units of Weight and Measure (the 1959 refinement of the yard and the pound, 24 FR 5348). nvlpubs.nist.gov/nistpubs/Legacy/MP/nbsmiscellaneouspub233.pdf
• NIST Special Publication 811, Guide for the Use of the International System of Units (2008), Appendix B: conversion factors to SI. nist.gov/pml/special-publication-811
• UK legislation, Weights and Measures Act 1985, Schedule 1, Part V: the pound as 0.45359237 kilogram and the stone as 14 pounds. legislation.gov.uk/ukpga/1985/72/schedule/1