From grams (g)
- Grams to Kilogramsg → kg
- Grams to Milligramsg → mg
- Grams to Poundsg → lb
- Grams to Ouncesg → oz
Mass conversion family
Mass unit conversions
Mass is the SI base quantity with dimension M; the kilogram (kg) is its SI base unit.
Five named units
Unit and factor reference
| Unit | Symbol | Factor to base | Relationship | Definition and variant |
|---|---|---|---|---|
| gram | g | 1 | defined | The gram is exactly 10⁻³ kilogram. SI mass multiples and submultiples are formed from the name gram and symbol g. The base factor is exactly 1 by the family base-unit choice; 1 g = 0.001 kg exactly. |
| kilogram | kg | 1000 | defined | The kilogram is the SI base unit of mass, defined through the fixed numerical value of the Planck constant; 1 kg = 1000 g exactly. The relationship to the gram base used by this family is exact. |
| milligram | mg | 0.001 | exact | A milligram is 10⁻³ gram and 10⁻⁶ kilogram: 1 mg = 0.001 g exactly. The decimal-prefix relationship is exact. |
| pound | lb | 453.59237 | defined | The pound in this family is the avoirdupois pound of mass, exactly 0.45359237 kg or 453.59237 g. Named variant: Avoirdupois pound mass; not pound-force, troy pound, or apothecaries pound. The terminating base factor is exact. |
| ounce | oz | 28.349523125 | defined | The ounce in this family is the avoirdupois ounce, one-sixteenth of an avoirdupois pound and exactly 28.349523125 g. Named variant: Avoirdupois ounce of mass; not a troy ounce, apothecaries ounce, or fluid ounce. The terminating base factor is exact. |
Every ordered pair
All 20 mass calculators
From kilograms (kg)
- Kilograms to Gramskg → g
- Kilograms to Milligramskg → mg
- Kilograms to Poundskg → lb
- Kilograms to Ounceskg → oz
From milligrams (mg)
- Milligrams to Gramsmg → g
- Milligrams to Kilogramsmg → kg
- Milligrams to Poundsmg → lb
- Milligrams to Ouncesmg → oz
From pounds (lb)
- Pounds to Gramslb → g
- Pounds to Kilogramslb → kg
- Pounds to Milligramslb → mg
- Pounds to Ounceslb → oz
From ounces (oz)
- Ounces to Gramsoz → g
- Ounces to Kilogramsoz → kg
- Ounces to Milligramsoz → mg
- Ounces to Poundsoz → lb
Evidence and review status
This family is machine-reviewed-pending-human. Automated checks verify structure, factor parity and source references; they do not constitute human or specialist approval.
Family assumptions and limits
- This family converts non-negative mass magnitudes; it does not convert force or infer local gravitational acceleration.
- Pound and ounce mean avoirdupois mass units, not pound-force, troy units, apothecaries units, or fluid ounces.
- A conversion preserves the source measurement's uncertainty and significant-figure limits.
Authoritative references
- The International System of Units (SI), 9th edition, version 4.01; Bureau International des Poids et Mesures; Section 2.3.1, kilogram definition on p. 127; Section 3, pp. 138 to 139, Table 7 and rule for forming decimal multiples/submultiples of mass from gram.; accessed 2026-08-07
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; Pages C-4, C-7, C-17 to C-19, and C-27; exact avoirdupois relationships 1 lb = 453.59237 g and 1 oz = 28.349523125 g, with naming guidance distinguishing mass systems.; accessed 2026-08-07