How do I convert Pound (lb) to Kilogram (kg)?

1 lb equals 0.453592 kg using SI-based conversion and precise factors.

What is the formula to convert Pound (lb) to Kilogram (kg)?

This is a linear unit conversion using a constant factor between units.

Yes, it uses exact definitions or standardized constants (e.g., 1 in = 25.4 mm).

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Category: Mass

Value From To Precision

0.453592 kg

1 lb = 0.453592 kg

High-precision rounding: 6 decimals

We convert by pivoting through the SI base unit for Mass and applying exact factors where applicable.

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Mass quantifies matter. The SI kilogram is defined via fundamental constants.

Pound (lb)

Imperial/US mass unit; 1 lb = 0.45359237 kg (exact).

History: Defined exactly in 1959; originates from Roman libra.

Kilogram (kg)

SI base unit of mass defined via Planck’s constant.

History: Since 2019 defined through h; before that, by the IPK artifact.