In electrostatics, what is the SI unit of electric dipole moment?

The SI unit of electric dipole moment is the coulomb-metre.

An electric dipole consists of two equal and opposite charges separated by a distance. Its dipole moment describes both the size of the charges and the separation between them, with direction conventionally pointing from the negative charge toward the positive charge. The unit is C·m.

Dipole moments help explain the behavior of polar molecules such as water. In an external electric field, a dipole tends to rotate so that its moment aligns with the field. The field can also exert different forces on the two charges when the field is nonuniform.

A common mix-up is the debye, a non-SI unit frequently used for molecular dipole moments. One debye is approximately 3.336 × 10⁻³⁰ coulomb-metres. Electric dipole moment is different from electric potential, which is measured in volts.