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Degree of Unsaturation Calculator

The degree of unsaturation, also known as the index of hydrogen deficiency or the double bond equivalent, is a measure used in organic chemistry to determine the number of pi bonds and rings present in a molecule. It is calculated from the molecular formula of the compound and is used to help draw the compound's structure.

Equation
Degree of Unsaturation
=
0.5
×
 
2
+2
×number of carbon atoms
-number of hydrogen atoms
+number of nitrogen atoms
-number of halogen atoms
 
Inputs
Degree of Unsaturation:
number of carbon atoms:
number of hydrogen atoms:
number of nitrogen atoms:
number of halogen atoms:

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References
This online resource may be cited as follows
MLA
"Quest CalculateDegree of Unsaturation Calculator." AAT Bioquest, Inc.30 Sep2025https://www.aatbio.com/tools/solve-equation-calculator/degree-of-unsaturation.
APA
AAT Bioquest, Inc. (2025September 30). Quest CalculateDegree of Unsaturation Calculator. AAT Bioquest. https://www.aatbio.com/tools/solve-equation-calculator/degree-of-unsaturation.
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