Bond Order Calculator
Use our bond order calculator to calculate bond order instantly from bonding and antibonding electrons. Includes how bond order is calculated, how to count bond order, the bond calculator formula, and examples (including MO diagram and Lewis structure context).
What Is Bond Order?
Bond order is a measure of the bond strength between two atoms. In general, a higher bond order means a stronger bond and a shorter bond length.
In molecular orbital (MO) theory, bond order is calculated using the difference between bonding electrons and antibonding electrons.
Students often use bond order to compare single, double, and triple bonds, and to analyze resonance structures, Lewis structures, and MO diagrams.
Bond Order Formula
The standard bond calculator formula from MO theory uses bonding and antibonding electrons.
This is the most common way to calculate bond order from an MO diagram (molecular orbital diagram).
If you have 10 bonding electrons and 6 antibonding electrons, the bond order is 2.
Different electron counts can still give the same bond order.
How to Use the Bond Order Calculator
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Enter the number of bonding electrons.
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Enter the number of antibonding electrons.
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The calculator applies the bond order formula: (bonding e⁻ − antibonding e⁻) ÷ 2.
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Read the bond order result and interpret it (higher bond order generally means a stronger bond).
Frequently Asked Questions
In MO theory, bond order is calculated as (bonding electrons − antibonding electrons) ÷ 2.
Count the electrons in bonding orbitals and antibonding orbitals on the MO diagram, then use: bond order = (bonding e⁻ − antibonding e⁻) ÷ 2.
For an MO approach, count bonding and antibonding electrons, then apply the formula. For Lewis/resonance structures, bond order is often the average number of bonds between the atoms across resonance forms.
For a single Lewis structure, bond order is usually 1 for a single bond, 2 for a double bond, 3 for a triple bond. With resonance structures, the bond order can be an average (for example, a bond that is single in one structure and double in another has an average bond order of 1.5).
Add the bond orders for the bond of interest across all resonance structures, then divide by the number of resonance structures (an average bond order).
Yes. In resonance (and in MO theory), bond order can be fractional (like 1.5), which reflects delocalized bonding.
No. This is a chemistry bond order calculator. Phrases like “calculate bond yield formula” refer to finance bonds, which are different from chemical bond order.