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Sources and Accuracy
Weight and mass conversions use kilogram as the reference unit. Common factors include 1 pound = 0.45359237 kilogram and 1 ounce = 0.028349523125 kilogram.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-05-21.
About These Units
kilogram [kg]
Definition
The kilogram is the SI base unit of mass and is the reference unit for the weight and mass converter.
History
The kilogram was historically tied to a physical prototype and is now defined using the Planck constant.
Current use
Kilograms are used for body weight, groceries, shipping, science, medicine, fitness, and commercial weighing.
ounce [oz]
Definition
The ounce is an avoirdupois mass unit equal to 28.349523125 grams.
History
The avoirdupois ounce became the standard ounce for general weight measurement.
Current use
Ounces are used for food packages, recipes, postal weights, consumer goods, and small shipments.