An electron configuration calculator writes the arrangement of electrons in an atom’s orbitals. Enter an element or atomic number, and it shows the full configuration, the shortened noble gas configuration and often an orbital diagram. It’s a core skill in chemistry classes.
Electrons fill orbitals in order of increasing energy, following the Aufbau principle: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p and so on. Each s orbital holds 2 electrons, p holds 6, d holds 10 and f holds 14. For example, iron (26 electrons) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶, or [Ar] 4s² 3d⁶ in noble gas shorthand.
Hund’s rule says electrons fill orbitals within a subshell singly before pairing, and the Pauli exclusion principle says each orbital holds at most two electrons with opposite spins. There are well-known exceptions: chromium is [Ar] 4s¹ 3d⁵ and copper is [Ar] 4s¹ 3d¹⁰, because half-filled and fully filled d subshells are especially stable.
For ions, add or remove electrons. When transition metals form cations, they lose 4s electrons before 3d electrons, so Fe²⁺ is [Ar] 3d⁶. Use the periodic table as a map: the blocks (s, p, d and f) show which subshell is being filled.
How to use the Electron Configuration Calculator on Minedit: enter your values in the fields, press calculate, and review the step-by-step breakdown under the result. If something looks off, change one input at a time to see how it affects the answer, which is also a great way to learn the math behind it.
Why use an online Electron Configuration Calculator: it saves time, avoids simple arithmetic mistakes and shows each step, so you can check your homework, plan a project or make a decision with confidence. Bookmark the page so it’s ready the next time you need it.
Learn more on Wikipedia’s electron configuration article. Find pH, stoichiometry and balancing equations calculators on Minedit.