Mass and Weight · Unit Converter

Convert Gram to Kilogram

Convert grams to kilograms instantly. 1 gram = 0.001 kilogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Kilogram to Gram converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.
Mass and Weight category 2 min read Published Last reviewed Updated

Units explained

Metric / SI

Gram

What is a gram?

The gram (g) equals one-thousandth of a kilogram.

Origin of the gram

From Late Latin 'gramma', a small weight or scruple.

Where it is used

The everyday metric unit for food, medicine, and small objects.

When and where it was developed

Defined in 1795 as the mass of one cubic centimeter of water at melting point.

Metric / SI

Kilogram

What is a kilogram?

The kilogram (kg) is the SI base unit of mass, defined by fixing the Planck constant h at 6.62607015E-34 J s.

Origin of the kilogram

From Greek 'khilioi' (thousand) plus 'gramma' (small weight).

Where it is used

The worldwide base unit of mass in science, commerce, and everyday life.

When and where it was developed

Adopted in 1795; redefined through the Planck constant on 20 May 2019.

Gram to Kilogram conversion formula

The relationship between grams and kilograms:

1 g = 0.001 kg
1 kg = 1000 g

To convert grams to kilograms, multiply the value in grams by 0.001. To reverse, multiply kilograms by 1000.

How to use this converter

Type a value into the calculator. The result in kilograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Kilogram to Gram converter for the reverse direction.

Step-by-step: convert grams to kilograms

  1. Write down the value in grams (g).
  2. Multiply that value by the factor 0.001.
  3. The product is the equivalent value in kilograms (kg).
  4. To reverse, multiply the kilogram value by 1000.

Worked examples

Example 1 — Convert 1 g to kg:
1 × 0.001 = 0.001 kg

Example 2 — Convert 100 g to kg:
100 × 0.001 = 0.1 kg

Real-world example — Furniture and large objects

A 72-gram piece of furniture converts to a value in kilograms that's easier to mentally compare with room dimensions. This is the typical workflow when shopping internationally and product specs use a different unit than your room measurements.

72 g × 0.001 = 0.072 kg

Real-world example — Children's height milestones

A 150-gram-tall child measures a value in kilograms that's commonly used for theme-park ride height requirements when travelling between countries that use different measurement units.

150 g × 0.001 = 0.15 kg

Real-world example — Body height conversion

You enter your height as 180 grams into an international job or visa application. The form then asks for the same value in kilograms — converting between these adjacent units is one of the most-used length conversions globally.

180 g × 0.001 = 0.18 kg

Gram to Kilogram conversion table

Standard reference values for converting grams to kilograms:

Gram [g]Kilogram [kg]
0.011e-5
0.10.0001
10.001
20.002
30.003
40.004
50.005
100.01
200.02
300.03
400.04
500.05
1000.1
5000.5
10001

Frequently asked questions

How many kilograms is 1 gram?
1 gram equals 0.001 kilogram.
How do I convert grams to kilograms?
Multiply the value in grams by 0.001 to get kilograms.
How do I convert kilograms back to grams?
Multiply the value in kilograms by 1000, or use the Kilogram to Gram converter.
How many kilograms is 100 grams?
100 grams equals 0.1 kilograms, because 100 × 0.001 = 0.1.

Convert Gram to other weight units

Show all Gram conversions
Metric / SI (17 units)
Avoirdupois (15 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Force / Engineering (5 units)

Sources & references

Conversion factor (1 g = 0.001 kg) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.