Planck constant = 6.626 070 15 × 10−34 J·s
- Symbol
- h
- Value
- 6.626 070 15 × 10−34
- Unit
- J·s
- Uncertainty
- exact (by definition)
- Copy-ready
6.62607015e-34
Defines the kilogram. Sets the energy of a photon of frequency f as E = hf.
NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.
The seven SI defining constants
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UsePhysics. "Planck constant — 6.626 070 15 × 10−34 J·s." UsePhysics.com. https://usephysics.com/reference/planck-constant. Value from the 2022 CODATA adjustment (NIST). Accessed [date].