Proxima Centauri is the closest star to our Sun, located just 4.25 light-years away in the constellation Centaurus. This red dwarf star hosts Proxima Centauri b, an Earth-sized exoplanet in its habitable zone. Use our calculator to find out how long the journey would take at different speeds.
Proxima Centauri is 4.2465 light-years from Earth. That is about 40.2 trillion km (25 trillion miles), or 268,600 astronomical units.
| Unit | Distance |
|---|---|
| Light-years | 4.2465 |
| Kilometers | 40,200,000,000,000 km |
| Miles | 25,000,000,000,000 miles |
| Astronomical units (AU) | 269,000 astronomical units |
| Parsecs | 1.3 |
Light from Proxima Centauri takes 4.2465 years to reach Earth, so the light you see tonight left Proxima Centauri 4.2465 years ago.
Voyager 1, the fastest object humans have sent into deep space, travels at about 17 km/s. It would need about 74,890 years to cover this distance.
Notable For: Closest star to the Sun, hosts exoplanet Proxima Centauri b
At the speed of light, it would take 4.25 years to reach Proxima Centauri from Earth. However, due to time dilation, a traveler moving at near-light speed would experience less time passing than observers on Earth.
With current spacecraft technology, it would take approximately 6,300 to 80,000 years to reach Proxima Centauri. Projects like Breakthrough Starshot aim to send tiny probes at 20% light speed, which would arrive in about 20 years.
Proxima Centauri is 4.2465 light-years from Earth, which is about 40.2 trillion km or 25 trillion miles. Light from Proxima Centauri takes 4.2465 years to reach us.
Proxima Centauri is 4.2465 light-years from Earth. One light-year is about 9.46 trillion km, the distance light travels in one year. In parsecs, Proxima Centauri is about 1.3 parsecs away.
This time dilation calculator lets you enter a distance in light-years and acceleration in m/s² to see how time dilation affects your journey. It shows differences between traveler and observer times, maximum velocity, energy requirements, Doppler shift, Lorentz factor, and how distances vary between reference frames. Charts appear after you calculate.
Time dilation is an effect from Einstein's theory of special relativity. The faster you move, the slower time passes for you compared to someone standing still. At 90% of light speed, time passes about 2.3 times slower for the traveler than for someone on Earth.
The Time Dilation Formula is:
Where:
t' = time measured by the observer (on Earth)
t = time experienced by the traveler
v = velocity of the traveler
c = speed of light (299,792,458 meters per second)