Constants & Units · constant
Planck mass
m_P = 2.176 434(24) × 10⁻⁸ kg
- Unit
- kg
- Value
- 2.176 434(24) × 10⁻⁸
- Exact
- no
- Note
- Surprisingly macroscopic — about the mass of a flea's egg, or 10¹⁹ protons.
- Symbol
- m_P
- Category
- Universal
- Numeric
- 2.176434e-08
- Uncertainty
- ±1.1 × 10⁻⁵ relative
Open on the Constants & Units shelf — the interactive card, the filters, and everything alongside it.