How to use this pound converter
Enter the value in pounds and select the required target unit. Kilograms are selected by default. Use a decimal such as 2.5 for two and a half pounds, or convert pounds and ounces to total ounces before entering a mixed measurement.
How the calculation works
The international avoirdupois pound is defined as exactly 0.45359237 kilogram. This exact relationship has been used for ordinary modern pound-to-metric conversion since the international yard and pound agreement. The calculator does not use a shortened 0.45 estimate internally.
One pound contains exactly 16 avoirdupois ounces. Because the pound definition is exact, one ounce equals exactly 28.349523125 grams. Troy pounds and troy ounces belong to a different system and are not represented by these unit labels.
The numerical result can contain more digits than a package label or household scale justifies. Preserve required tolerances and round at the final step. Do not use a general converter in place of certified weighing procedures.
Formulas
Pounds to kilograms
Pounds to grams
Pounds to ounces
Worked examples
Convert 150 pounds to kilograms
150 × 0.45359237 = 68.0388555 kilograms before rounding.
Convert 2.5 pounds to ounces
2.5 × 16 = exactly 40 ounces.
Convert 1 pound to grams
1 × 453.59237 = exactly 453.59237 grams under the international definition.
Common uses
Packages and luggage
Convert pound-based labels and limits to kilograms or grams before comparing them with metric requirements. Review the carrier's treatment of fractions and dimensional weight.
Food and household measurement
Translate mass quantities between pounds and metric units while keeping fluid volume and ingredient density outside the calculation.
Equipment and personal records
Convert stated masses for comparison, but retain the original unit and source conditions when tracking change over time.
Accuracy and limitations
The international avoirdupois pound is exactly 0.45359237 kilogram and contains exactly 16 avoirdupois ounces.
This page does not use troy, historical, or force pounds. Regulated measurements require the unit system and procedure named by the relevant authority.
Frequently asked questions
How many kilograms are in a pound?
One international avoirdupois pound equals exactly 0.45359237 kilogram.
How many ounces are in a pound?
There are exactly 16 avoirdupois ounces in one pound.
Does lb mean the same pound everywhere?
This tool uses the international avoirdupois pound. Historical, troy, and other specialized pounds are different units.
How do I enter pounds and ounces together?
Convert the ounces to pounds by dividing by 16, then add that value to the whole pounds; alternatively convert everything to ounces.
Can I use negative pounds?
The calculator accepts them mathematically, but a negative mass is generally meaningful only as a signed change or coordinate in a defined model.
Does the tool store my value?
No. The calculation is performed locally in your browser without saving the entered measurement.