Planck length
The Planck length is a scale formed from fundamental physical constants.
1.616 × 10⁻³⁵ mLengthBeyond the eye
Planck length vs Proton
What are they, and what does the difference actually look like?
Two things. One honest scale.
Meet the pair
What these two things are
Proton
A proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
1.682 fmDiameterThe diameter of Proton is about 1.04 × 10²⁰ times the length of Planck length.
01
Planck length1.616 × 10⁻³⁵ mLength
02
Proton1.682 fmDiameter
Inset ×3.62 × 10¹⁹Planck length is too small to see clearly at this scale. The ring marks its position; only the inset is enlarged.
Measurements, assumptions & sources +
Planck length
A theoretical scale formed from the speed of light, reduced Planck constant and gravitational constant. It is not experimentally established as the smallest possible length. The area and volume are derived mathematical scales.
NIST — 2022 CODATA fundamental constants
The marked length is calibrated. Unmeasured illustration details are representative.
Proton
Twice the approximately 0.8409 fm charge radius. The charge distribution has no hard boundary; the illustration is schematic.
NIST — 2022 CODATA fundamental constants
The marked diameter is calibrated. Unmeasured illustration details are representative.
Change the comparison
Put something else beside it.
Measurement details
Why these numbers?
The visual compares length with diameter. The records below preserve each value’s basis and caveats.
Planck length
1.616 × 10⁻³⁵ mLength · theoretical
A theoretical scale formed from the speed of light, reduced Planck constant and gravitational constant. It is not experimentally established as the smallest possible length. The area and volume are derived mathematical scales.
Proton
1.682 fmDiameter · measured constant
Twice the approximately 0.8409 fm charge radius. The charge distribution has no hard boundary; the illustration is schematic.
- Comparing
- Length ↔ Diameter
- Relative size
- Proton is larger on this measurement by a factor of about 1.04 × 10²⁰.
How to read the visual
The labelled spans and stored measurements determine the scale; unmeasured illustration details do not.
- Planck length is labelled theoretical; treat the displayed value as a comparison anchor rather than false precision.
- Proton is labelled measured constant; treat the displayed value as a comparison anchor rather than false precision.
There’s always another scale
Follow your curiosity.
Fundamental physicsPlanck length1.616 × 10⁻³⁵ mThe Planck length is a scale formed from fundamental physical constants.Fundamental physicsProton1.682 fmA proton is a positively charged particle found in the nucleus of atoms, made up of quarks.
MicroscopicHydrogen atom105.8 pmA hydrogen atom is the simplest neutral atom, with one proton in its nucleus and one electron around it.
SpaceObservable universe28.21 GpcThe observable universe is the region from which light or other signals have had time to reach us since the early universe.Fundamental physicsPlanck mass21.76 µgThe Planck mass is a theoretical mass scale derived from fundamental constants, significant in discussions of quantum gravity.
MicroscopicDNA double helix2 nmDNA is the molecule that stores hereditary information in living organisms.Side by side
Another point of view.
