Mass and Weight · Unit Converter

Convert Femtogram to Microgram

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

Femtogram

What is a femtogram?

A femtogram (fg) equals 10^-18 kilogram.

Origin of the femtogram

From the SI prefix 'femto-' (from Danish/Norwegian 'femten', fifteen).

Where it is used

Nanotechnology and high-sensitivity mass spectrometry.

When and where it was developed

The femto- prefix was adopted by the CGPM in 1975.

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.

Femtogram to Microgram conversion formula

The relationship between femtograms and micrograms:

1 fg = 1e-9 µg
1 µg = 1e+9 fg

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

How to use this converter

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

Step-by-step: convert femtograms to micrograms

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

Worked examples

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

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

Real-world example — Wavelengths across the spectrum

Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 femtograms can be re-expressed in micrograms for direct comparison with another instrument's calibration data sheet.

800 fg × 1e-9 = 8e-7 µg

Real-world example — Molecular dimensions

The diameter of small molecular structures (around 2 femtograms) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.

2 fg × 1e-9 = 2e-9 µg

Femtogram to Microgram conversion table

Standard reference values for converting femtograms to micrograms:

Femtogram [fg]Microgram [µg]
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 micrograms is 1 femtogram?
1 femtogram equals 1e-9 microgram.
How do I convert femtograms to micrograms?
Multiply the value in femtograms by 1e-9 to get micrograms.
How do I convert micrograms back to femtograms?
Multiply the value in micrograms by 1e+9, or use the Microgram to Femtogram converter.
How many micrograms is 100 femtograms?
100 femtograms equals 1e-7 micrograms, because 100 × 1e-9 = 1e-7.

Convert Femtogram to other weight units

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

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