Mass and Weight · Unit Converter

Convert Femtogram to Grain

Convert femtograms to grains instantly. 1 femtogram = 1.543236e-14 grain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Grain 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.

Avoirdupois

Grain

What is a grain?

The grain (gr) equals 1/7000 of an avoirdupois pound, about 64.8 milligrams.

Origin of the grain

Based on the nominal mass of a single barley grain.

Where it is used

Ammunition and bullet mass, archery, and historical pharmacy.

When and where it was developed

Standardized through the English avoirdupois system and retained in 1959.

Femtogram to Grain conversion formula

The relationship between femtograms and grains:

1 fg = 1.543236e-14 gr
1 gr = 6.47989e+13 fg

To convert femtograms to grains, multiply the value in femtograms by 1.543236e-14. To reverse, multiply grains by 6.47989e+13.

How to use this converter

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

Step-by-step: convert femtograms to grains

  1. Write down the value in femtograms (fg).
  2. Multiply that value by the factor 1.543236e-14.
  3. The product is the equivalent value in grains (gr).
  4. To reverse, multiply the grain value by 6.47989e+13.

Worked examples

Example 1 — Convert 1 fg to gr:
1 × 1.543236e-14 = 1.543236e-14 gr

Example 2 — Convert 100 fg to gr:
100 × 1.543236e-14 = 1.543236e-12 gr

Real-world example — Spanning sub-micron to micron scale

Crossing from femtograms to grains is the everyday workflow of microscopy and semiconductor engineering — a measurement of 1000 femtograms translates to a much more compact value in grains that fits the scale of biological cells and process nodes.

1000 fg × 1.543236e-14 = 1.543236e-11 gr

Real-world example — Sub-visible-light wavelength

500 femtograms (the green-yellow visible band) equals 0.5 grains — the canonical conversion in optics between wavelength specifications and micron-scale lens-coating thicknesses.

500 fg × 1.543236e-14 = 7.71618e-12 gr

Femtogram to Grain conversion table

Standard reference values for converting femtograms to grains:

Femtogram [fg]Grain [gr]
0.011.543236e-16
0.11.543236e-15
11.543236e-14
23.086472e-14
34.629708e-14
46.172944e-14
57.71618e-14
101.543236e-13
203.086472e-13
304.629708e-13
406.172944e-13
507.71618e-13
1001.543236e-12
5007.71618e-12
10001.543236e-11

Frequently asked questions

How many grains is 1 femtogram?
1 femtogram equals 1.543236e-14 grain.
How do I convert femtograms to grains?
Multiply the value in femtograms by 1.543236e-14 to get grains.
How do I convert grains back to femtograms?
Multiply the value in grains by 6.47989e+13, or use the Grain to Femtogram converter.
How many grains is 100 femtograms?
100 femtograms equals 1.543236e-12 grains, because 100 × 1.543236e-14 = 1.543236e-12.

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 = 1.543236e-14 gr) verified against the following authoritative sources:

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