Fine-structure constant = 7.297 352 5643 × 10−3 (dimensionless)
- Symbol
- α
- Value
- 7.297 352 5643 × 10−3
- Unit
- (dimensionless)
- Uncertainty
- 0.000 000 0011 × 10⁻³
- Copy-ready
7.2973525643e-3
The strength of the electromagnetic interaction. Being dimensionless, it has the same value in every unit system.
NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.
Atomic and electromagnetic constants
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UsePhysics. "Fine-structure constant — 7.297 352 5643 × 10−3 (dimensionless)." UsePhysics.com. https://usephysics.com/reference/fine-structure-constant. Value from the 2022 CODATA adjustment (NIST). Accessed [date].