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?
Fleeting instants
1 tP
5.3912 × 10⁻⁴⁴ sseconds
1.4976 × 10⁻⁴⁷ hhours
6.2399 × 10⁻⁴⁹ daysdays
1.7084 × 10⁻⁵¹ yearsyears
01
1 Planck time5.391 × 10⁻⁴⁴ sTime · definition
02
Planck length5.391 × 10⁻⁴⁴ sTime · theoretical
Both timelines start together. Length measures elapsed time, not a physical distance.
A little perspective
1 Planck time and Planck length have approximately the same time.
Measurements, assumptions & sources +
1 Planck time
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 time is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
The visual compares time with time. The records below preserve each value’s basis and caveats.
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
- 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
Put it next to…
Choose a suggestion to redraw the comparison, or open its page to learn what it is.
A little smaller. A little larger.