Dipole Moment Calculator — Electric Dipole p = qd
The electric dipole moment quantifies how strongly a pair of equal and opposite charges separated by a distance are polarised. Enter the charge magnitude and the separation distance to get the dipole moment in both Debye (the chemistry standard) and C·m (SI).
C
m
Display result in
Debye (D) — standard unit in chemistry
- 1
Dipole moment in C·m
|q| × d = 1.602e-19 × 1.000e-10 = 1.6020e-29p = |q| × d — the product of charge magnitude and separation distance. - 2
Convert to Debye (÷ 3.336×10⁻³⁰)
1.6020e-29 ÷ 3.336×10⁻³⁰ = 4.8027
How does this calculator work?
Electric dipole moment p = q × d, where q is the charge magnitude (C) and d is the separation distance (m). Convert to Debye by dividing by 3.336 × 10⁻³⁰. Typical molecular dipoles are 0–10 D. The moment vector points from negative to positive charge.
Formula
How this is calculated
An electric dipole consists of two equal and opposite charges +q and −q separated by a distance d. The electric dipole moment p = q × d points from the negative charge to the positive charge and has units of coulomb-metres (C·m) in the SI system. In chemistry, dipole moments are conventionally expressed in Debye (D), where 1 D = 3.33564 × 10⁻³⁰ C·m. For reference, a proton–electron pair separated by 1 Å (10⁻¹⁰ m) gives p = 1.602 × 10⁻¹⁹ × 10⁻¹⁰ = 1.602 × 10⁻²⁹ C·m ≈ 4.80 D.
In molecules, the dipole moment arises from the unequal sharing of electrons in bonds. Symmetric molecules (CO₂, CH₄) have zero net dipole; asymmetric ones (H₂O ≈ 1.85 D, HCl ≈ 1.08 D, HF ≈ 1.91 D) have non-zero moments. The molecular dipole moment is the vector sum of all individual bond dipoles.
This calculator treats the simple two-charge model p = |q| × d, which is exact for a point-dipole model. Real molecular dipoles require quantum-chemical calculations of electron density distributions; the formula gives good estimates for simple polar bonds.
Frequently asked questions
The Debye (D) is the CGS unit of electric dipole moment, equal to 3.33564 × 10⁻³⁰ C·m. It is convenient in chemistry because typical bond dipole moments are 0–10 D. For example, water has a dipole moment of 1.85 D and HF has 1.91 D.
Yes — it is a vector quantity pointing from the negative to the positive charge (physics convention) or the reverse in some chemistry conventions. For molecular dipole moments, the individual bond vectors must be added as vectors, taking into account the 3-D geometry of the molecule.
Only molecules with a non-zero dipole moment can absorb microwave radiation and show pure rotational spectra. Changes in dipole moment during molecular vibration determine which IR modes are active. The dipole moment also governs intermolecular forces such as dipole–dipole interactions and Keesom forces.
TG we-Calculate Editorial Team. (2026). Dipole Moment Calculator — Electric Dipole p = qd [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/dipole-moment-calculator
TG we-Calculate Editorial Team. "Dipole Moment Calculator — Electric Dipole p = qd." TG we-Calculate. 2026. https://we-calculate.com/calculator/dipole-moment-calculator.
TG we-Calculate Editorial Team, "Dipole Moment Calculator — Electric Dipole p = qd," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/dipole-moment-calculator
@misc{wecalculate_dipole_moment_calculator, title = {Dipole Moment Calculator — Electric Dipole p = qd}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/dipole-moment-calculator}}, year = {2026}, note = {TG we-Calculate} }
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