Convert Microgram to Femtogram
Convert micrograms to femtograms instantly. 1 microgram = 1e+9 femtogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Femtogram to Microgram converter for the reverse conversion.
Units explained
Microgram
A microgram (ug) equals 10^-9 kilogram, or one-millionth of a gram.
From the SI prefix 'micro-' (from Greek 'mikros', small).
Trace nutrients, potent drug doses, and environmental contaminant levels.
The micro- prefix was incorporated into the SI in 1960.
Femtogram
A femtogram (fg) equals 10^-18 kilogram.
From the SI prefix 'femto-' (from Danish/Norwegian 'femten', fifteen).
Nanotechnology and high-sensitivity mass spectrometry.
The femto- prefix was adopted by the CGPM in 1975.
Microgram to Femtogram conversion formula
The relationship between micrograms and femtograms:
To convert micrograms to femtograms, multiply the value in micrograms by 1e+9. To reverse, multiply femtograms by 1e-9.
How to use this converter
Type a value into the calculator. The result in femtograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Femtogram to Microgram converter for the reverse direction.
Step-by-step: convert micrograms to femtograms
- Write down the value in micrograms (µg).
- Multiply that value by the factor 1e+9.
- The product is the equivalent value in femtograms (fg).
- To reverse, multiply the femtogram value by 1e-9.
Worked examples
Example 1 — Convert 1 µg to fg:
1 × 1e+9 = 1e+9 fg
Example 2 — Convert 100 µg to fg:
100 × 1e+9 = 1e+11 fg
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 micrograms can be re-expressed in femtograms for direct comparison with another instrument's calibration data sheet.
800 µg × 1e+9 = 8e+11 fg
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 micrograms) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 µg × 1e+9 = 2e+9 fg
Microgram to Femtogram conversion table
Standard reference values for converting micrograms to femtograms:
| Microgram [µg] | Femtogram [fg] |
|---|---|
| 0.01 | 1e+7 |
| 0.1 | 1e+8 |
| 1 | 1e+9 |
| 2 | 2e+9 |
| 3 | 3e+9 |
| 4 | 4e+9 |
| 5 | 5e+9 |
| 10 | 1e+10 |
| 20 | 2e+10 |
| 30 | 3e+10 |
| 40 | 4e+10 |
| 50 | 5e+10 |
| 100 | 1e+11 |
| 500 | 5e+11 |
| 1000 | 1e+12 |
Frequently asked questions
How many femtograms is 1 microgram?
How do I convert micrograms to femtograms?
How do I convert femtograms back to micrograms?
How many femtograms is 100 micrograms?
Popular weight unit conversions
Convert Microgram to other weight units
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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)
Sources & references
Conversion factor (1 µg = 1e+9 fg) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.