1 Planck time
5.391 × 10⁻⁴⁴ sTime · definition
A theoretical scale made from physical constants. It is not a proven smallest object or a hard physical limit.
Time
Just how long is 1 Planck time?
A duration of 1 Planck time is about 5.391247 × 10⁻⁴⁴ seconds.
Fleeting instants
1 tP
ELAPSED TIME
1 Planck time
A theoretical scale made from physical constants.
5.391 × 10⁻⁴⁴ sTime
0
Planck length
The Planck length is a scale formed from fundamental physical constants.
5.391 × 10⁻⁴⁴ sTime
0
Both timelines start together. Length measures elapsed time, not a physical distance.
A little perspective
1 Planck time is approximately equal to the duration of the Planck length.
Measurements, assumptions & sources +
1 Planck time
Time: 5.391 × 10⁻⁴⁴ s; definition.
A theoretical scale made from physical constants. It is not a proven smallest object or a hard physical limit.
Planck length
Time: 5.391 × 10⁻⁴⁴ s; 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 time is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
Compare 1 Planck time with the duration of the Planck length. The notes below explain how each value was chosen.
Planck length
5.391 × 10⁻⁴⁴ sTime · 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
- Time ↔ Time
- Relative size
- 1 Planck time is approximately equal to the duration of 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 duration of the Planck length: This is a theoretical value calculated under stated physical assumptions, not a direct observation.
A duration is an interval, not a calendar date.
5.3912 × 10⁻⁴⁴ sseconds
1.4976 × 10⁻⁴⁷ hhours
6.2399 × 10⁻⁴⁹ daysdays
1.7084 × 10⁻⁵¹ yearsyears
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