13.8 billion years
13.8 GyrTime · definition
Time conversions use a Julian year of exactly 365.25 days.
Time
Just how long is 13.8 billion years?
Deep time
13.8 Gyr
4.3549 × 10¹⁷ sseconds
1.2097 × 10¹⁴ hhours
5.0405 × 10¹² daysdays
1.38 × 10¹⁰ yearsyears
01
13.8 billion years13.8 GyrTime · definition
02
Observable universe13.8 GyrAge · cosmological estimate
Both timelines start together. Length measures elapsed time, not a physical distance.
A little perspective
The time of 13.8 billion years and the age of Observable universe are approximately the same.
Measurements, assumptions & sources +
13.8 billion years
Time conversions use a Julian year of exactly 365.25 days.
Observable universe
About 92 billion light-years across in present-day comoving distance. Space expanded while the light travelled. The 13.8-billion-year age is a time, not its radius divided by light speed. The total universe may be far larger, possibly infinite.
The marked age is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
The visual compares time with age. The records below preserve each value’s basis and caveats.
Observable universe
13.8 GyrAge · cosmological estimate
About 92 billion light-years across in present-day comoving distance. Space expanded while the light travelled. The 13.8-billion-year age is a time, not its radius divided by light speed. The total universe may be far larger, possibly infinite.
- Comparing
- Time ↔ Age
- 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.
- Observable universe is labelled cosmological estimate; 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.