Calculate double bond equivalent (degree of unsaturation) from molecular formulas. Free DBE calculator for structure elucidation in organic chemistry—determine rings and double bonds instantly.
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DBE (also called degree of unsaturation) tells you the total count of rings plus double bonds in a molecule—calculated directly from the molecular formula.
The formula is:
DBE Formula:
DBE = 1 + (C + N + P + Si) - (H + F + Cl + Br + I)/2
Higher DBE values indicate more unsaturation—more rings and double bonds in the structure. DBE = 4 often signals aromatic character, while DBE = 0 means fully saturated.
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