Mass and Weight · Unit Converter

Convert Gram to Femtogram

Convert grams to femtograms instantly. 1 gram = 1e+15 femtogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Femtogram 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

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.

Gram to Femtogram conversion formula

The relationship between grams and femtograms:

1 g = 1e+15 fg
1 fg = 1e-15 g

To convert grams to femtograms, multiply the value in grams by 1e+15. To reverse, multiply femtograms by 1e-15.

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 Gram converter for the reverse direction.

Step-by-step: convert grams to femtograms

  1. Write down the value in grams (g).
  2. Multiply that value by the factor 1e+15.
  3. The product is the equivalent value in femtograms (fg).
  4. To reverse, multiply the femtogram value by 1e-15.

Worked examples

Example 1 — Convert 1 g to fg:
1 × 1e+15 = 1e+15 fg

Example 2 — Convert 100 g to fg:
100 × 1e+15 = 1e+17 fg

Real-world example — Centimeter to wavelength scale

One gram equals 10 million femtograms. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.

1 g × 1e+15 = 1e+15 fg

Real-world example — Small-scale to atomic-scale

One gram equals 10 million femtograms — useful for physics curricula that relate everyday measurements to atomic and optical scales.

1 g × 1e+15 = 1e+15 fg

Gram to Femtogram conversion table

Standard reference values for converting grams to femtograms:

Gram [g]Femtogram [fg]
0.011e+13
0.11e+14
11e+15
22e+15
33e+15
44e+15
55e+15
101e+16
202e+16
303e+16
404e+16
505e+16
1001e+17
5005e+17
10001e+18

Frequently asked questions

How many femtograms is 1 gram?
1 gram equals 1e+15 femtogram.
How do I convert grams to femtograms?
Multiply the value in grams by 1e+15 to get femtograms.
How do I convert femtograms back to grams?
Multiply the value in femtograms by 1e-15, or use the Femtogram to Gram converter.
How many femtograms is 100 grams?
100 grams equals 1e+17 femtograms, because 100 × 1e+15 = 1e+17.

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 = 1e+15 fg) verified against the following authoritative sources:

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