1 Planck length
1.616 × 10⁻³⁵ mLength · definition
A theoretical scale made from physical constants. It is not a proven smallest object or a hard physical limit.
Length & distance
Just how long is 1 Planck length?
Fundamental
1 ℓP
1 Planck length
A theoretical scale made from physical constants.
1.616 × 10⁻³⁵ mLength
0 - shared origin
Planck length
The Planck length is a scale formed from fundamental physical constants.
1.616 × 10⁻³⁵ mLength
0 - shared origin
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions. A ruler represents the selected distance or a measurement not visible in this view.
A little perspective
1 Planck length is approximately equal to the Planck length.
Measurements, assumptions & sources +
1 Planck length
Length: 1.616 × 10⁻³⁵ m; definition.
A theoretical scale made from physical constants. It is not a proven smallest object or a hard physical limit.
Planck length
Length: 1.616 × 10⁻³⁵ m; 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.
NIST — 2022 CODATA fundamental constants
The marked length is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
Compare 1 Planck length with the Planck length. The notes below explain how each value was chosen.
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.
- Comparing
- Length ↔ Length
- Relative size
- 1 Planck length is approximately equal to the Planck length.
How to read the visual
The diagram uses the recorded measurements. Details outside the marked spans do not set the scale.
- The Planck length: This is a theoretical value calculated under stated physical assumptions, not a direct observation.
This comparison follows the selected length only; other dimensions may differ.
1.6163 × 10⁻³⁵ mmetres
5.3027 × 10⁻³⁵ ftfeet
1.0043 × 10⁻³⁸ mimiles
1.0804 × 10⁻⁴⁶ AUastronomical units
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