Physical constants sheet

28 rows · EngiRef · sample of the first 8 rows

Physical constants sheet. Every constant in the reference, grouped by family: symbol, value at the source's own precision, and unit — the sheet to tape inside a lab notebook rather than look up one at a time.
Constant	Symbol	Value	Unit
Fundamental
Speed of Light in Vacuum	c	299792458	m/s
Planck Constant	h	6.62607015 × 10⁻³⁴	J·s
Reduced Planck Constant	ℏ	1.054571817 × 10⁻³⁴	J·s
Elementary Charge	e	1.602176634 × 10⁻¹⁹	C
Avogadro's Constant	Nᴀ	6.02214076 × 10²³	1/mol
Gravitational Constant	G	6.6743 × 10⁻¹¹	N·m²/kg²
Fine Structure Constant¹	α	0.0072973525693	not defined
Electromagnetic
Vacuum Permittivity	ε₀	8.8541878128 × 10⁻¹²	F/m

Values are printed exactly as stored, unrounded; large and small magnitudes are shown in ×10ⁿ form. The 2019 SI redefinition fixed several of these exactly — check each constant's own page for whether its value is defined or measured.

The constants library records no unit string for this entry; read its definition on the free constant page before using it in a calculation.

Reference values are provided for study and quick reference. Verify against current standards and manufacturer data before safety-critical design.

Every figure on this sheet is also free to read on its own reference page — browse the free reference. Premium pays for the format, not the facts.