Use our orbital diagram calculator for quick and accurate calculations. Free online tool.
The Orbital Diagram Calculator generates a visual box-and-arrow diagram showing how electrons are individually assigned to each atomic orbital. Unlike a simple electron configuration string, orbital diagrams display each orbital as a box and each electron as an arrow pointing up (spin +½) or down (spin −½). Enter any atomic number from 1 to 118 to see the complete ground-state orbital diagram with subshell-by-subshell breakdown.
Orbital diagrams are built using Hund's rule of maximum multiplicity: electrons occupy every orbital of a given subshell singly before any orbital receives a second electron, and all singly occupied orbitals have parallel spins. For example, nitrogen (Z=7) has the configuration 1s²2s²2p³ — its three 2p electrons each occupy a separate 2p orbital with spin-up arrows: ↑ | ↑ | ↑, rather than pairing two electrons in one box.
Accepted inputs include atomic numbers (1–118) or element symbols. The calculator outputs a subshell-by-subshell orbital diagram with explicit spin arrows, the total number of unpaired electrons (which determines magnetic properties), and the resulting electron configuration string. It is widely used in general chemistry courses for understanding paramagnetism, valence bond theory, and molecular orbital theory.
Electron configuration, orbital diagrams, valence electrons, and electron arrangement
Explore CategoryAn orbital diagram represents each orbital as a box and each electron as an arrow, showing the specific spin (up ↑ or down ↓) of every electron rather than just counting how many electrons are in each subshell.
Hund's rule states that electrons fill orbitals of equal energy one at a time with parallel spins before pairing up. In an orbital diagram for carbon (2p²), the two 2p electrons appear in separate boxes both pointing up, not paired in one box.
Count all boxes that contain exactly one arrow. For example, oxygen (2p⁴) has two paired and two unpaired 2p electrons, giving it two unpaired electrons and making it paramagnetic.
Spin directions are shown because the Pauli exclusion principle requires that two electrons sharing the same orbital must have opposite spins, a detail that a plain configuration notation like 2p² cannot convey.
An electron configuration (e.g., 2p³) tells you the number of electrons in a subshell, while an orbital diagram shows how those electrons are distributed among individual orbitals and specifies each electron's spin state.