How to Use This Tool
Use the kilograms or pounds box for a direct conversion. For the British stone-and-pounds format, enter whole stones and the remaining pounds in the paired fields. The converter keeps kilograms, pounds, and stone-plus-pounds visible together, so you can read the same mass in the form you need.
The three boxes are all live
Type in any one and the other two follow immediately. The stone field is split in two so you can enter
11 and 4 the way you would say it. Underneath, the panel writes the weight out in
plain words, which is the form you actually need when reading it aloud or filling in a form that expects
stones and pounds separately.
The exact factors
One avoirdupois pound equals 0.45359237 kg; one stone equals 14 pounds, or 6.35029318 kg. The conversion factors are exact, while displayed values are rounded: kilograms and decimal pounds to two decimals, pounds remaining in stone format to one decimal, and ounces to one decimal. For example, the 2.2 shortcut gives 154.00 lb for 70 kg; the exact conversion is 154.32 lb. A 23 kg baggage allowance converts to about 50.71 lb, while 50 lb converts to 22.68 kg.
Show pounds and ounces
To read a kilogram conversion as pounds and ounces, keep the whole-pound part of the unrounded result, then multiply the fractional-pound remainder by 16. For example, 70 kg is about 154.3236 lb, which displays as 154 lb 5.2 oz. Ounces are rounded to one decimal place; if rounding reaches 16 oz, the display carries one pound forward.
The mistake this prevents
“11.3 stone” means 11 st 4.2 lb because 0.3 × 14 = 4.2. By comparison, 11 st 3 lb is 11.21 decimal stone. Those values differ by 1.2 lb, so the decimal and mixed formats should not be interchanged.
The difference tracker
Enter a target in kilograms, pounds, or decimal stones to see the difference from the current value in all three units. The selected target unit is converted to kilograms before the difference is calculated.
What this tool will not do
This page converts units only. It does not assess body composition or give a health interpretation of a weight.
Reference: the NIST Handbook 44 conversion table lists the avoirdupois pound as 0.45359237 kg. The stone-and-pound values are calculated from 14 pounds per stone.
