Mass Converter

Convert mass units. Exact factors, a quick reference table and worked examples.

1 kg = 2.204623 lb

The same value in every unit

UnitSymbolValue
Milligrammg1 000 000
Gramg1 000
Kilogramkg1
Tonnet0.001
Ounceoz35.27396
Poundlb2.204623
Slugslug0.06852177
Short ton (US)short ton0.001102311
Long ton (UK)long ton0.0009842065

How to convert mass units

Every mass unit is related to one base unit (Kilogram, kg) by an exact factor. To convert, multiply by the factor of the unit you start from and divide by the factor of the unit you want.

value in new unit = value × (factor of old unit ÷ factor of new unit)

For example, 1 kg = 1 kg and 1 lb = 0.4535924 kg, so 1 kg = 2.204623 lb.

Quick reference table

How many of the units in the column headings make up one of the unit in each row.

One…= mg= g= kg= t= oz= lb
1 mg10.0011 × 10⁻⁶1 × 10⁻⁹3.5274 × 10⁻⁵2.20462 × 10⁻⁶
1 g1 00010.0011 × 10⁻⁶0.035273960.002204623
1 kg1 000 0001 00010.00135.273962.204623
1 t1 × 10⁹1 000 0001 000135 273.962 204.623
1 oz28 349.5228.349520.028349522.83495 × 10⁻⁵10.0625
1 lb453 592.4453.59240.45359240.0004535924161
1 slug14 593 90314 593.914.59390.0145939514.784832.17405
1 short ton907 184 740907 184.7907.18470.907184732 0002 000
1 long ton1.01605 × 10⁹1 016 0471 016.0471.01604735 8402 240

Common values: kg to lb

Kilogram (kg)Pound (lb)
1 kg2.204623 lb
2 kg4.409245 lb
5 kg11.02311 lb
10 kg22.04623 lb
20 kg44.09245 lb
50 kg110.2311 lb
100 kg220.4623 lb
200 kg440.9245 lb
500 kg1 102.311 lb
1 000 kg2 204.623 lb

Worked examples

Convert 1 kg to lb

  • 1 kg = 1 kg and 1 lb = 0.4535924 kg.
  • 1 × 1 ÷ 0.4535924 = 2.204623 lb.

Convert 50 kg to mg

  • 1 kg = 1 kg and 1 mg = 1 × 10⁻⁶ kg.
  • 50 × 1 ÷ 1 × 10⁻⁶ = 50 000 000 mg.

Convert 250 long ton to g

  • 1 long ton = 1 016.047 kg and 1 g = 0.001 kg.
  • 250 × 1 016.047 ÷ 0.001 = 254 011 727 g.

The units explained

UnitSymbolExact factorWhere it is used
Milligrammg1 mg = 1 × 10⁻⁶ kgLab, pharmaceuticals
Gramg1 g = 0.001 kgSmall parts, lab
Kilogramkg1 kg = 1 kgSI unit
Tonnet1 t = 1 000 kgHeavy goods, steel
Ounceoz1 oz = 0.02834952 kgUS small items
Poundlb1 lb = 0.4535924 kgUS weights
Slugslug1 slug = 14.5939 kgUS dynamics (F = m a)
Short ton (US)short ton1 short ton = 907.1847 kgUS freight
Long ton (UK)long ton1 long ton = 1 016.047 kgUK shipping

Key facts

  • 1 lb = 0.45359237 kg exactly. 1 kg = 2.2046 lb.
  • Mass is not weight: weight (a force) = m × g, with g = 9.80665 m/s².

FAQ

How many Pound units are in one Kilogram?

1 kg = 2.204623 lb.

How do I convert kg to lb?

Multiply by 2.204623 (the factor 1 ÷ 0.4535924). To go back, divide by 2.204623 or multiply by 0.4535924.

What is the milligram (mg) used for?

Lab, pharmaceuticals.

What is the gram (g) used for?

Small parts, lab.

Are the conversion factors exact?

Where a unit is defined exactly (the inch is 25.4 mm, the pound is 0.45359237 kg, standard gravity is 9.80665 m/s²) the factor is exact; others are given to ten or more digits. Results are shown to seven significant digits.

References

  • NIST Special Publication 811, Guide for the Use of the International System of Units (SI), and NIST Handbook 44, Appendix C (general tables of units of measurement).
  • BIPM, The International System of Units (SI Brochure), 9th edition; ISO 80000 (quantities and units).

Last reviewed: November 2026.