Grau insaturação (DBE)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Degree of Unsaturation (DBE) calculator determines the number of rings and multiple bonds in an organic molecule. The formula is DBE = (2C + 2 + N - H - X)/2, where C is carbon, H is hydrogen, N is nitrogen, and X represents halogens (F, Cl, Br, I).
To use it, input the molecular formula with counts for carbon, hydrogen, nitrogen, and halogens. DBE indicates aromatic rings (requires ≥3) and double/triple bonds. Fractional results are rounded, as non-integer values suggest invalid structures.
This tool is commonly used in mass spectrometry, NMR spectroscopy, and molecular formula validation. However, it ignores oxygen, sulfur, and other elements that don't affect unsaturation. Use it as a guide, but always cross-check with experimental methods.
Note: The calculation assumes an accurate molecular formula. If the molecule contains unlisted heteroatoms (e.g., phosphorus) or complex structures, DBE may be inaccurate. It is not applicable to inorganic or aqueous compounds.
Frequently asked questions
What is the Degree of Unsaturation (DBE)?
It calculates the number of rings and multiple bonds (double/triple) in a molecule using its molecular formula.
How to use the calculator?
Enter carbon, hydrogen, nitrogen, and halogen counts from the molecular formula. Oxygen, sulfur, and other elements are ignored.
What does a DBE of 0 mean?
The molecule is fully saturated, with no rings or multiple bonds.
Why is the result a decimal?
Fractional values are invalid. Round to the nearest integer and recheck the molecular formula.