Estimate the percent ionic character of a bond from the two atoms’ Pauling electronegativity values, with the bond type.
Percent ionic character
How to use this tool
Enter each atom’s Pauling electronegativity.
Read the percent ionic character and the complementary percent covalent character.
Use the type label as a rough classification, not a sharp boundary.
Repeat with other atom pairs to rank bonds by polarity.
Formula & worked example
Sodium (0.93) and chlorine (3.16) differ by 2.23, giving about 71% ionic character.
Limitations — read this before you rely on it
Pauling’s empirical formula only. It does not account for molecular environment, and the 0.4/1.7 type cut-offs are conventions.
Frequently asked questions
It is Pauling’s empirical estimate of how much ionic character a bond has, from 0% (purely covalent) to near 100% (fully ionic).
Real bonds form a continuum and the formula is an empirical fit, not a measurement of actual charge separation.
Differences below 0.4 are usually called nonpolar covalent, 0.4–1.7 polar covalent, and above 1.7 predominantly ionic. These are conventions, not sharp physical boundaries.
Use a standard Pauling-scale table: for example H 2.20, C 2.55, N 3.04, O 3.44, F 3.98, Na 0.93, Cl 3.16.
No. Even NaCl has significant covalent character in the gas phase; the percentage is a model estimate, not a claim that the bond is purely ionic.