How strong are hydrogen bonds compared with covalent bonds?

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Hydrogen bonds are significantly weaker than covalent bonds. While a typical covalent bond has a bond energy of approximately 70 to 110 kilocalories per mole, a hydrogen bond has a strength of only about 5 kilocalories (21 kilojoules) per mole.1

Covalent bonds involve the sharing of electrons between atoms to form a stable molecule. In contrast, a hydrogen bond is a much weaker electrostatic attraction between a hydrogen atom—which is already covalently bonded to a highly electronegative atom like oxygen, nitrogen, or fluorine—and another electronegative atom. Because of this difference in strength, hydrogen bonds are classified as intermolecular forces, which are generally much weaker than the chemical bonds that hold atoms together within a molecule.234567