Mass and Weight · Unit Converter

Convert Microgram to Kilogram

Convert micrograms to kilograms instantly. 1 microgram = 1e-9 kilogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Kilogram to Microgram 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

Microgram

What is a microgram?

A microgram (ug) equals 10^-9 kilogram, or one-millionth of a gram.

Origin of the microgram

From the SI prefix 'micro-' (from Greek 'mikros', small).

Where it is used

Trace nutrients, potent drug doses, and environmental contaminant levels.

When and where it was developed

The micro- prefix was incorporated into the SI in 1960.

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.

Microgram to Kilogram conversion formula

The relationship between micrograms and kilograms:

1 µg = 1e-9 kg
1 kg = 1e+9 µg

To convert micrograms to kilograms, multiply the value in micrograms by 1e-9. To reverse, multiply kilograms by 1e+9.

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 Microgram converter for the reverse direction.

Step-by-step: convert micrograms to kilograms

  1. Write down the value in micrograms (µg).
  2. Multiply that value by the factor 1e-9.
  3. The product is the equivalent value in kilograms (kg).
  4. To reverse, multiply the kilogram value by 1e+9.

Worked examples

Example 1 — Convert 1 µg to kg:
1 × 1e-9 = 1e-9 kg

Example 2 — Convert 100 µg to kg:
100 × 1e-9 = 1e-7 kg

Real-world example — Bridging nine orders of magnitude

500 million micrograms equals a value comfortably in the human-scale kilograms range. Physics problems that span this gap are common when comparing the wavelength of light to the path length of an experiment.

5e+8 µg × 1e-9 = 0.5 kg

Real-world example — From sub-micron to human scale

One billion micrograms equals one kilogram — the conversion that drives home the gulf between atomic-scale features and everyday objects in physics curricula.

1e+9 µg × 1e-9 = 1 kg

Microgram to Kilogram conversion table

Standard reference values for converting micrograms to kilograms:

Microgram [µg]Kilogram [kg]
0.011e-11
0.11e-10
11e-9
22e-9
33e-9
44e-9
55e-9
101e-8
202e-8
303e-8
404e-8
505e-8
1001e-7
5005e-7
10001e-6

Frequently asked questions

How many kilograms is 1 microgram?
1 microgram equals 1e-9 kilogram.
How do I convert micrograms to kilograms?
Multiply the value in micrograms by 1e-9 to get kilograms.
How do I convert kilograms back to micrograms?
Multiply the value in kilograms by 1e+9, or use the Kilogram to Microgram converter.
How many kilograms is 100 micrograms?
100 micrograms equals 1e-7 kilograms, because 100 × 1e-9 = 1e-7.

Convert Microgram to other weight units

Show all Microgram 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 µg = 1e-9 kg) verified against the following authoritative sources:

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