The hybridization calculator determines the hybridization state, electron geometry, molecular geometry, and bond angles for 40+ common molecules. Enter a molecule formula or manually set bonding/lone pairs using the VSEPR steric number method.
Molecule Input
Hybridization Results
How to Use the Hybridization Calculator
The hybridization calculator uses VSEPR theory to determine how atomic orbitals combine to form the observed molecular geometry. It handles all common hybridization types from sp to sp3d2.
Step 1: Enter the Molecule
Type a molecule formula in the input box (e.g., H2O, NH3, BF3) or click one of the quick-select buttons. Alternatively, manually enter the number of bonding pairs and lone pairs on the central atom to calculate any hybridization directly.
Step 2: Understand the Steric Number
The steric number = bonding groups + lone pairs on the central atom. This determines hybridization: steric number 2 → sp (linear), 3 → sp2 (trigonal planar), 4 → sp3 (tetrahedral), 5 → sp3d (trigonal bipyramidal), 6 → sp3d2 (octahedral).
Water (H₂O) Example
Oxygen has 6 valence electrons. In H₂O: 2 electrons form 2 O-H bonds (2 bonding pairs), and 4 remaining electrons form 2 lone pairs. Steric number = 2 + 2 = 4, so oxygen is sp3 hybridized. The 4 pairs arrange tetrahedrally, but the 2 lone pairs compress the H-O-H angle from 109.5° to ~104.5°.
Carbon in Different Hybridization States
Carbon's hybridization depends on its bonding: In CH₄ (methane), carbon has 4 single bonds → sp3 (tetrahedral, 109.5°). In C₂H₄ (ethylene), each carbon has 3 groups (2 H + 1 double bond) → sp2 (trigonal planar, 120°). In C₂H₂ (acetylene), each carbon has 2 groups (1 H + 1 triple bond) → sp (linear, 180°).
Expanded Octets (sp3d and sp3d2)
Elements in period 3 and beyond can use d orbitals to accommodate more than 8 electrons. PCl₅ (sp3d, trigonal bipyramidal) has 5 bonding pairs and no lone pairs. SF₄ (sp3d, see-saw) has 4 bonding pairs and 1 lone pair. SF₆ (sp3d2, octahedral) has 6 bonding pairs and no lone pairs.
FAQ
What is hybridization in chemistry?
Hybridization is the concept of mixing atomic orbitals to form new hybrid orbitals used for bonding. sp hybridization mixes 1 s and 1 p orbital (linear geometry, 180°); sp2 mixes 1 s and 2 p orbitals (trigonal planar, 120°); sp3 mixes 1 s and 3 p orbitals (tetrahedral, 109.5°).
How do you calculate hybridization from a formula?
Count the steric number: bonding groups + lone pairs on the central atom. Steric number 2 = sp (linear), 3 = sp2 (trigonal planar), 4 = sp3 (tetrahedral), 5 = sp3d (trigonal bipyramidal), 6 = sp3d2 (octahedral). Lone pairs affect molecular geometry but not hybridization type.
Why does H2O have sp3 hybridization but a bent shape?
Oxygen in H2O has 4 electron pairs: 2 bonding pairs (O-H bonds) and 2 lone pairs. Steric number = 4, so hybridization is sp3. The 4 pairs arrange tetrahedrally, but the 2 lone pairs are invisible in the molecular geometry, making the shape V-bent with bond angle ~104.5° (less than 109.5° due to lone pair repulsion).
What is the difference between electron geometry and molecular geometry?
Electron geometry describes the arrangement of ALL electron pairs (bonding + lone pairs) around the central atom. Molecular geometry describes only the arrangement of ATOMS (ignoring lone pairs). For NH3, electron geometry is tetrahedral (4 pairs), but molecular geometry is trigonal pyramidal (3 H atoms + 1 lone pair).
Is this hybridization calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
What molecules have sp3d hybridization?
sp3d hybridization (steric number 5) occurs in expanded octet molecules like PCl5 (trigonal bipyramidal), SF4 (see-saw), ClF3 (T-shaped), and XeF2 (linear). These use d orbitals and only occur in period 3 and higher elements.
How does hybridization affect bond angles?
Ideal bond angles: sp = 180°, sp2 = 120°, sp3 = 109.5°, sp3d = 90°/120°, sp3d2 = 90°. Actual angles differ when lone pairs are present, as lone pairs exert greater repulsion than bonding pairs. In H2O, the ideal sp3 angle of 109.5° is compressed to ~104.5° by two lone pairs.