Boltzmann Constant

Converts between temperature and typical thermal energy per particle, fixed exactly to define the kelvin.

Specifications & Metrics

symbol

k_B

status

Exact — SI defining constant (2019)

value

1.380649 × 10⁻²³ J·K⁻¹

Relative Scale in Constants

Core Principles & Analysis

• Converts temperature into typical thermal energy per particle through E ≈ k_B·T.
• Carved on Boltzmann's Vienna tombstone in the form S = k log W.
• Fixed exactly in 2019, redefining the kelvin in terms of energy.

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