Planck length: how big is it?
Planck length is about 1.6 × 10⁻³⁵ m. In everyday terms, that is ≈ 6,630,000,000,000 trillion times smaller than a hydrogen atom.
- Size
- 1.6 × 10⁻³⁵ m
- In metres
- 1.60 × 10⁻³⁵ m
- Everyday comparison
- ≈ 6,630,000,000,000 trillion times smaller than a hydrogen atom
- Chapter
- The Planck Scale
Did you know?
The smallest length physics can meaningfully describe. Below it, the very idea of distance may stop making sense.
How it compares
- About 63,000 trillion× smaller than Quark (upper limit) (1.0 × 10⁻¹⁸ m).
Other things of a similar size
- Quark (upper limit) 1.0 × 10⁻¹⁸ m
- Proton 1.7 fm
- Helium nucleus 3.4 fm
- Uranium nucleus 15 fm
- Hydrogen atom 106 pm
- Water molecule 275 pm
Sizes are rounded, typical values drawn from standard reference sources, including NIST/CODATA physical constants and NASA's planetary fact sheets. Real objects vary; see About for how sizes are chosen.