# Convert g to kg

Please provide values below to convert gram [g] to kilogram [kg], or *vice versa*.

### Gram

**Definition:** A gram (symbol: g) is a unit of mass in the International System of Units (SI). The definition of the gram is based on the kilogram, where a gram is one thousandth of a kilogram, the SI base unit of mass. Since 2019, the definition of the kilogram is no longer based on the international prototype, and rather is based on Planck's constant, h, along with the new definitions of the second and the meter.

**History/origin:** Originally, a gram was defined as the absolute weight of pure water in a cubic centimeter at the temperature of melting ice (later 4 °C). The gram used to be a fundamental unit of mass as part of centimeter-gram-second systems of units up until the widespread adoption of SI, which uses kilograms as the base unit of mass. The gram was later redefined as one thousandth of a kilogram, the SI (meter-kilogram-second system of units) base unit of mass.

**Current use:** The gram is widely used in every life as well as scientific contexts. For example, the gram is typically used to measure non-liquid ingredients used for cooking or groceries. Standards on the nutrition labels of food products often require the relative contents to be stated per 100 grams of the product.

### Kilogram

**Definition:** A kilogram (symbol: kg) is the base unit of mass in the International System of Units (SI). It is currently defined based on the fixed numerical value of the Planck constant, h, which is equal to 6.62607015 × 10^{-34} in the units of J·s, or kg·m^{2}·s^{-1}. The meter and the second are defined in terms of c, the speed of light, and cesium frequency, ΔνCs. Even though the definition of the kilogram was changed in 2019, the actual size of the unit remained the same. The changes were intended to improve the definitions of SI base units, not to actually change how the units are used throughout the world.

**History/origin:** The name kilogram was derived from the French "kilogramme," which in turn came from adding Greek terminology meaning "a thousand," before the Late Latin term "gramma" meaning "a small weight."

Unlike the other SI base units, the kilogram is the only SI base unit with an SI prefix. SI is a system based on the meter-kilogram-second system of units rather than a centimeter-gram-second system. This is at least in part due to the inconsistencies and lack of coherence that can arise through use of centimeter-gram-second systems, such as those between the systems of electrostatic and electromagnetic units.

The kilogram was originally defined as the mass of one liter of water at its freezing point in 1794, but was eventually re-defined, since measuring the mass of a volume of water was imprecise and cumbersome.

A new definition of the kilogram was introduced in 2019 based on Planck's constant and changes to the definition of the second. Prior to the current definition, the kilogram was defined as being equal to the mass of a physical prototype, a cylinder made of a platinum-iridium alloy, which was an imperfect measure. This is evidenced by the fact that the mass of the original prototype for the kilogram now weighs 50 micrograms less than other copies of the standard kilogram.

**Current use:** As a base unit of SI, the kilogram is used globally in nearly all fields and applications, with the exception of countries like the United States, where the kilogram is used in many areas, at least to some extent (such as science, industry, government, and the military) but typically not in everyday applications.

### Gram to Kilogram Conversion Table

Gram [g] | Kilogram [kg] |
---|---|

0.01 g | 1.0E-5 kg |

0.1 g | 0.0001 kg |

1 g | 0.001 kg |

2 g | 0.002 kg |

3 g | 0.003 kg |

5 g | 0.005 kg |

10 g | 0.01 kg |

20 g | 0.02 kg |

50 g | 0.05 kg |

100 g | 0.1 kg |

1000 g | 1 kg |

### How to Convert Gram to Kilogram

1 g = 0.001 kg

1 kg = 1000 g

**Example:** convert 15 g to kg:

15 g = 15 × 0.001 kg = 0.015 kg