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
1.6163 × 10⁻³⁵ mmetres
5.3027 × 10⁻³⁵ ftfeet
1.0043 × 10⁻³⁸ mimiles
1.0804 × 10⁻⁴⁶ AUastronomical units
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1 Planck length1.616 × 10⁻³⁵ mLength · definition
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Planck length1.616 × 10⁻³⁵ mLength · theoretical
Both marked spans share one linear scale. Artwork keeps its proportions; poses and surface detail are illustrative.
A little perspective
1 Planck length and Planck length have approximately the same length.
Measurements, assumptions & sources +
1 Planck length
A theoretical scale made from physical constants. It is not a proven smallest object or a hard physical limit.
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.
Measurement details
Why these numbers?
The visual compares length with length. 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.
- Comparing
- Length ↔ Length
- Relative size
- The two selected measurements are approximately equal.
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.
Change your perspective
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Choose a suggestion to redraw the comparison, or open its page to learn what it is.
A little smaller. A little larger.