Enter pounds and optional ounces to find the matching weight in kilograms, or switch directions to convert kilograms to pounds.
Advanced options
Table of contents
How to use our Pounds to Kg Converter
- Choose the conversion direction that matches the unit shown on your scale, label, form, or limit.
- For pounds to kilograms, enter the pounds value. If the source also lists ounces, enter them separately; otherwise leave ounces blank.
- For kilograms to pounds, enter the value in kilograms. The pound and ounce fields are not used in this direction.
- Open Advanced options only if you need a different number of digits after the decimal point, then select Calculate.
- Check that the result unit matches the unit your form or task needs. For a pounds-and-ounces entry, use the decimal-pound supporting value to confirm the ounces were added correctly.
Definitions
Pound (lb): A US customary mass unit. One international avoirdupois pound is exactly 0.45359237 kilogram.
Kilogram (kg): The metric mass unit used for the converted result.
Ounce (oz): One sixteenth of an ordinary avoirdupois pound. This converter uses ounces only as the second part of a pounds-and-ounces entry.
Decimal pounds: Pounds written with a decimal point. For example, 3.5 lb equals 3 lb 8 oz.
Result decimal places: The number of digits displayed after the decimal point. This setting changes rounding, not the conversion itself.
Common mistakes and quick fixes
Mistake: Entering 3.8 pounds when the source says 3 lb 8 oz.
Fix: Check Conversion direction and then recalculate. Enter 3 for pounds and 8 for ounces. Decimal pounds and ounces are not the same thing.
Mistake: Entering 16 or more ounces.
Fix: Check Conversion direction and then recalculate. Carry each full 16 ounces into pounds. For 7 lb 16 oz, enter 8 lb and leave ounces blank or enter 0.
Mistake: Entering a negative pound or kilogram value.
Fix: Check Conversion direction and then recalculate. Enter 0 or a positive number. This converter accepts nonnegative measurements only.
Mistake: Typing 1,01 or 2,50 for a decimal value.
Fix: Check Conversion direction and then recalculate. Use commas only for thousands, such as 1,000. Use a decimal point for decimals, such as 1.01 or 2.50.
Mistake: Treating a rounded kilogram or pound result as the full converted value.
Fix: Check Conversion direction and then recalculate. Choose more result decimal places when a form or later calculation needs more detail. Rounding changes only what is shown.
Limitations & Key Assumptions / Boundary Conditions
- This converter uses international avoirdupois pounds and ordinary ounces. Do not use it for troy ounces or troy pounds used for precious metals.
- Enter the weight stated by your scale, label, or record. The calculation does not account for scale error, clothing, packaging, or a difference between labeled and measured mass.
- Ounces must be from 0 up to, but not including, 16. Enter 16 ounces as one additional pound.
- Results are rounded to the selected number of decimal places. Choose more decimal places if a form or later calculation requires them.
- Weights must be 0 or greater. Negative values are outside this converter's measurement range.
Methodology
Conversion method
The calculator combines the pound value and optional ounces, then converts the combined amount using the exact factor 1 lb = 0.45359237 kg. A blank ounces field counts as 0 ounces.
total pounds = pounds + ounces / 16
kilograms = total pounds * 0.45359237
For the reverse direction, the calculator divides kilograms by 0.45359237. Display rounding is applied only after the calculation.
pounds = kilograms / 0.45359237
Worked example
For 3 lb 8 oz, 8 ounces equals 8 / 16, or 0.5 lb. The combined value is 3.5 lb. Multiplying 3.5 by 0.45359237 gives 1.587573295 kg, which displays as 1.588 kg with three decimal places.