Convert kg to lbs

Kilogram

Definición

A kilogram (symbol: kg) is the fundamental unit of mass in the International System of Units (SI). Since May 20 2019, its value has been anchored to Planck’s constant (h = 6.62607015 × 10⁻³⁴ J·s), while the metre and the second are defined via the speed of light and the cesium-133 hyperfine transition. Although the formal definition shifted, the size of one kilogram remains exactly the same worldwide.

Origin

The word “kilogram” comes from the French kilogramme, itself built from the Greek kilo- (“thousand”) and the Late Latin gramma (“small weight”). Initially (1794), a kilogram was set equal to the mass of one litre of water at its freezing point, but that approach proved too imprecise for high-precision science.

Modern Definition

Until 2019, the kilogram was represented by a platinum-iridium cylinder stored near Paris. Over time, tiny mass drifts appeared between that prototype and its replicas. Tying the kilogram to a fixed numerical value of Planck’s constant removed any reliance on a physical artifact.

Usage

Today, the kilogram underpins virtually all mass measurements—industrial, scientific, commercial—across the globe. In everyday life, nearly every country uses kilograms exclusively, although in the United States pounds remain common for routine weighing.

Pound

Definición

The pound (symbol: lb) is a unit of mass in both the British imperial and U.S. customary systems. The international avoirdupois pound is defined as exactly 0.45359237 kg and divides into 16 avoirdupois ounces.

History

The pound traces back to the Roman libra. During the Middle Ages, Europe saw many local pounds until the 13th-century adoption of the avoirdupois system, which standardized a pound of 16 ounces—a choice that eased fractional arithmetic since 16 divides evenly by 2, 4, and 8. This system was internationally formalized in 1959.

Usage

In the United States, pounds remain the default for body weight, groceries, and general commerce. In the United Kingdom, although metric units dominate, food packaging still shows pounds (alongside kilograms), and people often state body weight in stones (1 stone = 14 lb).

Kilogram ⇄ Pound Conversion Table

Cómo convertir

• 1 kg = 2.2046226218 lb

• 1 lb = 0.45359237 kg

Ejemplo
To convert 15 kg into pounds:

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