How Many Miles Have You Travelled Around the Sun? • The Science 360

While you read this sentence, Earth carries you about 150 km round the Sun. By the end of today it will be 2.57 million km, about 1.6 million miles. By your next birthday it will be close to 584 million miles, a full lap of an orbit 93 million miles in radius. Nobody feels it, because the motion is almost perfectly steady.

This post works out the yearly and lifetime numbers in miles and kilometres, shows the two ways to get them, and explains why the even bigger galactic figures cannot simply be piled on top. The cosmic odometer runs the same sums for your birth date and ticks forward live while you watch.

Quick answerEarth moves round the Sun at an average 29.78 km/s, which is 18.5 miles per second or about 66,600 mph. That carries you 584 million miles (940 million km) every year. Multiply by your age: a 30-year-old has travelled about 17.5 billion miles round the Sun, and an 80-year-old about 46.7 billion miles.

How many miles does Earth travel around the Sun in a year?

There are two independent ways to get the answer, and they agree.

The first uses Earth's speed. NASA's Earth fact sheet gives the mean orbital velocity as 29.78 km/s. Multiply by the number of seconds in a year, using 365.25 days so leap years are included:

Example 1: from Earth's speed

\begin{aligned} t &= 365.25 \times 86{,}400 = 31{,}557{,}600 \text{ s} \\ d &= 29.78 \times 31{,}557{,}600 = 9.398 \times 10^{8} \text{ km} \\ &= \frac{9.398 \times 10^{8}}{1.609344} = 5.840 \times 10^{8} \text{ miles} \end{aligned}

So 939.8 million km or 584.0 million miles a year. Per day it is 2.57 million km (1.60 million miles), per hour 107,208 km (66,616 miles).

The second uses the size of the orbit. Earth's average distance from the Sun is 149.598 million km, and its orbit is so close to a circle (eccentricity 0.0167) that the circumference is within 0.01% of a circle's:

Example 2: from the size of the orbit

\begin{aligned} C &= 2\pi a = 2\pi \times 149.598 \times 10^{6} \text{ km} \\ &= 9.400 \times 10^{8} \text{ km} = 584.1 \text{ million miles} \\ v &= \frac{C}{365.256 \times 86{,}400 \text{ s}} = 29.78 \text{ km/s} \end{aligned}

Dividing the circumference by the sidereal year of 365.256 days gives back the fact sheet's 29.78 km/s, which is a nice check that the two numbers belong together.

One year round the Sun in miles: a single loop of Earth's path round the Sun, with odometers reading 583,555,833 miles round the Sun, 6,909,565 miles from Earth's spin in New York, 4,683,339,298 miles round the Milky Way and a net 7.247 billion miles against the microwave background — Figure 1. From 13 November 2025 to 13 November 2026 (365 days): 583.6 million miles round the Sun, 6.9 million miles of spin in New York, 4.68 billion miles round the Milky Way. Open this in the calculator.

How many miles have I travelled around the Sun in my life?

Multiply your age by 584 million miles. Here are the totals for common ages, using years of 365.25 days.

Age	Miles round the Sun	Kilometres round the Sun
1	584.0 million	939.8 million
5	2.920 billion	4.699 billion
10	5.840 billion	9.398 billion
18	10.51 billion	16.92 billion
21	12.26 billion	19.74 billion
30	17.52 billion	28.19 billion
40	23.36 billion	37.59 billion
50	29.20 billion	46.99 billion
65	37.96 billion	61.09 billion
80	46.72 billion	75.18 billion
100	58.40 billion	93.98 billion

Example 3: a 30th birthday, exact to the day

From 13 November 1996 to 13 November 2026 is 10,957 days, which is 946,684,800 seconds.

\begin{aligned} d &= 29.78 \times 946{,}684{,}800 \\ &= 28{,}192{,}273{,}344 \text{ km} \\ &= 17.52 \text{ billion miles} \end{aligned}

That is about 73,000 trips from Earth to the Moon, or 188 times the distance from Earth to the Sun.

How far a 30-year-old in London has travelled through space: Earth's path drawn as a coil of 30 laps round the moving Sun, with odometers reading 28,192,273,344 km round the Sun, 274,095,447 km from Earth's spin, 226,257,667,200 km round the Milky Way and 534,876,912,000 km through space, and a net 350.1 billion km against the microwave background — Figure 2. A 30-year-old in London: 28.19 billion km round the Sun in 30 laps, 274 million km of spin and 226 billion km round the Milky Way. Open this in the calculator.

How fast is Earth moving around the Sun in mph?

About 66,600 mph on average. The orbit is slightly elliptical, so the speed changes through the year. NASA lists a maximum of 30.29 km/s and a minimum of 29.29 km/s:

When	Distance from the Sun	Speed	In mph
Early January (perihelion)	147.1 million km	30.29 km/s	67,760 mph
Average	149.6 million km	29.78 km/s	66,616 mph
Early July (aphelion)	152.1 million km	29.29 km/s	65,520 mph

The difference is a little over 3%, and it evens out over each full year, so lifetime totals use the average. Earth moving fastest in January, during the northern winter, surprises a lot of people; distance from the Sun is not what makes the seasons. The full story of the 3% distance change is in how orbital eccentricity changes sunlight, and every other speed Earth has, with how it is measured, is in how fast is Earth moving.

Does Earth’s spin add more miles?

A little, and it depends on where you live. The equator is 40,075 km round and turns once every 23.93 hours relative to the stars, so the ground there moves at 465 m/s, about 1,040 mph. Away from the equator the circle you ride on is smaller by the cosine of your latitude.

v = 465.1 \text{ m/s} \times \cos\varphi

At London's 51.5 degrees that is 290 m/s, which over 30 years adds 274 million km. On the equator it would be 440 million km, and at the North Pole nothing at all. Even the equator's figure is under 2% of the distance round the Sun, and it goes round in a daily loop rather than taking you anywhere.

A 10-year-old in Mumbai has been carried 9,396,566,784 km round the Sun in 10 laps, 138,675,484 km by Earth's spin at 439 m/s, and 75,412,339,200 km round the Milky Way, with a net 116.7 billion km against the microwave background — Figure 3. A 10-year-old in Mumbai, at 19.1 degrees north: 9.40 billion km round the Sun and 139 million km from the spin at 439 m/s. Open this in the calculator.

Are you back where you started after a year?

Only relative to the Sun, and that is the most common misconception about orbits. The Sun is moving too. Table 3 of the Planck 2018 overview paper, which collects the best values for these motions, gives the Sun's neighbourhood a speed of 239 ± 5 km/s round the centre of the Milky Way. In one year that is 7.54 billion km, about 50 times the Earth to Sun distance. So by your first birthday Earth has gone once round the Sun, but the Sun and Earth are 4.7 billion miles further along their path round the galaxy.

Your real path is a long, stretched spiral. The calculator draws it as a coil, one turn per year, squashed along its length so it fits on a screen. At true scale each turn would be 50 times longer than it is wide, more like a gently wavy line. NASA puts one lap of the galaxy at about 230 million years, so a whole human life covers about one part in three million of it.

Why can’t you add the galaxy and the cosmos to your total?

Because the motions point in different directions and are measured against different things. Planck's table lists the Milky Way's centre moving at 565 ± 5 km/s relative to the cosmic microwave background. Add 29.78, 0.47, 239 and 565 km/s and you get about 834 km/s, but the speed of the Sun actually measured against the microwave background, from the Doppler shift of that radiation, is 369.82 ± 0.11 km/s.

The reason is that the Sun's orbit round the galaxy points about 150 degrees away from the galaxy's own motion, so the two partly cancel. Velocities combine like arrows placed nose to tail. The redshift and blueshift post explains how a Doppler shift turns into a speed in the first place.

\left|\vec v_1 + \vec v_2\right| \le |\vec v_1| + |\vec v_2|

Over 30 years the honest net figure, your straight-line distance from where you were born measured in the frame of the microwave background, is 350.1 billion km. Adding the separate odometers would claim 790 billion km.

An 80-year-old's path through space as a tight coil of 80 laps round the Sun, with odometers reading 46,716,442,376 miles round the Sun, 553,143,848 miles of spin, 374,923,765,211 miles round the Milky Way and a net 580.1 billion miles, not the 1.31 trillion miles you get by adding — Figure 4. Eighty years in miles: 46.7 billion round the Sun, 375 billion round the galaxy, and a net 580 billion against the microwave background, not the 1.31 trillion you get by adding. Open this in the calculator.

Try it with your own birth date

Open the cosmic odometer set to miles, type your birth date and latitude, and leave the "as of" box empty. The drums count up in real time, about 18.5 miles every second for the trip round the Sun, and the working below the results shows each multiplication.

Cosmic odometer calculator for a 30-year-old on the equator: 28.19 billion km round the Sun, 226 billion km round the Milky Way, 535 billion km through the cosmos, 440 million km from Earth's spin at 465 m/s and a net 350 billion km against the microwave background, with the working shown — Figure 5. The full calculator for a 30-year-old on the equator, with the working: 28.19 billion km round the Sun and 440 million km of spin. Open this in the calculator.

Sources

NASA NSSDCA, Earth Fact Sheet: mean orbital velocity 29.78 km/s (maximum 30.29, minimum 29.29), semimajor axis 149.598 million km, sidereal year 365.256 days, equatorial radius 6,378.137 km, sidereal rotation 23.9345 hours.
Planck Collaboration, Planck 2018 results I, Overview, Section 3 and Table 3: Sun relative to the CMB 369.82 ± 0.11 km/s; local standard of rest round the galactic centre 239 ± 5 km/s; galactic centre relative to the CMB 565 ± 5 km/s; Local Group relative to the CMB 620 ± 15 km/s.
NASA Science, Sun facts: about 230 million years for one trip round the Milky Way.

Frequently asked questions

How many miles do you travel around the Sun in a year?

About 584 million miles, or 940 million km. Earth’s mean orbital speed is 29.78 km/s (18.5 miles per second), and a year has about 31.56 million seconds.

How many miles have I travelled around the Sun in my lifetime?

Multiply your age in years by 584 million. A 30-year-old has gone about 17.5 billion miles, a 50-year-old about 29.2 billion and an 80-year-old about 46.7 billion miles.

How fast does Earth travel around the Sun in miles per hour?

About 66,600 mph on average. The speed varies from about 65,500 mph in early July, when Earth is farthest from the Sun, to about 67,800 mph in early January, when it is closest.

Do you end up back where you started after a year?

Only relative to the Sun. While Earth goes once round, the Sun moves about 7.5 billion km (4.7 billion miles) round the Milky Way, so your path through the galaxy is a stretched spiral that never closes.

Can I add the distance round the Sun to the distance round the galaxy?

No. The motions point in different directions and are measured against different things. The one speed measured against a single reference, the cosmic microwave background, is 369.8 km/s for the Sun, much less than the separate speeds added together.