weight unit converter

Convert Mass units, compare 21 unit definitions and explore formulas, examples and common questions.

Mass converter

Worked example1 lb ≈ 0.453592 kg
Converted value

1Pounds≈0.453592Kilos

Enter a finite value between 0 and 1 trillion, with up to 8 decimal places.

Auto mode preserves significant digits for small values; manual mode rounds to the selected decimal places. ≈ means approximate; < means below the display limit. Extreme values use × 10ⁿ. Calculations are rounded only for display.

Complete unit directory21 units

Choose a source unit to see every available target unit. Each directory has a stable address.

How to use this calculator

  1. Enter the value you want to convert.
  2. Choose the source and target units, then adjust the display precision if needed.
  3. Read the result. Select Convert to open a page for this value, or use the table below.

Definitions and assumptions

This category converts mass relative to kilograms. Avoirdupois and troy measures have different definitions. The kilonewton mass equivalent assumes standard gravity of 9.80665 m/s²; a force is not intrinsically a mass.

Frequently asked questions

Which Mass units are supported?

The directory lists 21 units, including symbols and availability. Choose any source unit to browse its target units.

how to convert lb to kg?

The calculator converts the input to the category's reference unit, then divides by the target unit's factor. 1 × 0.45359237 ≈ 0.453592 Kilos. Use the source and target factors shown in the formula. The worked example uses the value on this page, and the table provides other common values.

Are troy ounces and ordinary ounces the same?

No. A troy ounce is 31.1034768 grams, while an avoirdupois ounce is 28.349523125 grams. Choose the convention used by your source.

Why is the displayed result rounded?

Auto mode preserves significant digits for small values; manual mode rounds to the selected decimal places. ≈ means approximate; < means below the display limit. Extreme values use × 10ⁿ. Calculations are rounded only for display.

What input range can I use?

This calculator accepts non-negative values up to 1 trillion, with up to 8 decimal places. It does not calculate signed vectors or calendar date intervals.

Why is a unit unavailable?

A conversion is unavailable when a verified unit definition or a current exchange-rate value has not been configured. The tool does not invent a coefficient.

Sources and methodology

Methods and sources · Content revised

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