Bond Order Calculator
Enter the number of electrons in bonding molecular orbitals and antibonding molecular orbitals to find the bond order. Bond order gives a simple picture of bond strength within this model.
Last updated: September 26, 2026
Frequently asked questions
What is bond order?
Bond order is a measure, from molecular orbital theory, of the number of chemical bonds between two atoms. It is calculated as (bonding electrons − antibonding electrons) / 2.
What do bonding and antibonding electrons mean?
Bonding electrons occupy molecular orbitals that are lower in energy and stabilize the bond between atoms. Antibonding electrons occupy higher-energy orbitals that weaken or oppose the bond.
Is this the same as Bond Duration?
No. Bond Duration on this site is a finance calculator for the interest-rate sensitivity of a bond investment. This calculator is about the chemistry concept of a bond between atoms.
What does a bond order of zero mean?
A bond order of zero means the bonding and antibonding electrons cancel out, and the species is not expected to form a stable bond in this simple model, like He₂.
Can bond order be a fraction?
Yes. Species with an odd number of electrons, such as O₂⁻ or O₂⁺, have half-integer bond orders.
Does a higher bond order always mean a more reactive molecule?
Not necessarily. Bond order relates to bond strength and length in this simplified model, but reactivity depends on many other factors, including orbital energies, sterics, and the rest of the molecule.