Spin · Orbit · Galaxy · CMB
You sit in your chair and feel nothing. Yet right now you are spinning with Earth, falling around the Sun, circling the centre of the galaxy and gliding through the universe against the oldest observable light. Pick a place and see all four speeds on a single ruler — then switch the frame of reference and watch the answer change.
Pick a place to see your speeds.
Four speeds, four frames of reference · sources at the end
Each arrow is one of your speeds, on a logarithmic scale — from hundreds to over a million kilometres per hour. Go down step by step: each stop lights one arrow and says what it is measured against.
Speed one · changes with place
In Bucharest, you turn with Earth at 1,195.7 km/h — 98% of the speed of sound. At the Equator it would be 1,674.4 km/h, at the poles zero: the speed falls with the cosine of latitude, and your place sits 44.43 degrees from the Equator.
Measured against Earth's centre.
NASA Earth Fact Sheet · this page's computation
Speed two · the same for everyone
Earth carries you around the Sun at 29.78 km/s — 107,208 km/h. Every day, the orbit alone takes you 64 times around the Equator's length. That is about 88 times the speed of sound and a hundredth of a percent of light speed.
Measured against the Sun's centre.
NASA Earth Fact Sheet
Speed three · the same for everyone
The galaxy's circular speed at the Sun is about 230 km/s: 824,400 km/h. Two modern teams measure 229 (formal ±0.2, systematics 2–5%) and 240 (±8); the page works with 229, to which the Sun adds its own 17.9 km/s motion. One full circuit takes about 220 million years (208 at 240 km/s).
Measured against the centre of the galaxy.
Eilers et al. 2019 · Reid et al. 2014
Speed four · the same for everyone
Against the oldest observable light, the Sun moves at 369.82 km/s — 1,331,352 km/h, the fastest speed on the ruler: 0.12% of light speed, toward the constellation Crater. Earth rocks 30 km/s around that speed through the year.
Measured against the rest frame of the CMB.
Planck 2018 · COBE 1993
“How fast am I moving?” has no single answer. Pick the frame of reference and the page gives your speed against it.
Against Earth's centre you move at 1,195.7 km/h — the spin of Bucharest.
Earth turns under you once per sidereal day; that is all that is left when you forget everything else.
Against the Sun you move at 29.78 km/s — 107,208 km/h, between 29.29 and 30.29 through the orbital year.
The orbit's 29.78 km/s gains or loses up to 0.5 km/s of spin, depending on the time of day.
Against the centre of the galaxy, the circular speed at the Sun is about 230 km/s — 824,400 km/h; the Sun adds its own 17.9 km/s motion against its neighbourhood.
Earth's orbit around the Sun is an invisible doodle next to a 220-million-year galactic circuit.
Against the CMB you move at 369.82 km/s — 1,331,352 km/h, plus or minus Earth's 30 km/s of orbit, depending on the season.
You travel with the Sun, while Earth's orbit adds or subtracts up to 30 km/s, depending on the season.
All four answers are true at once. That is why the page refuses to give you just one.
| Bucharest | 1,195.7 km/h |
| Cluj-Napoca | 1,146.8 km/h |
| Iași | 1,138.5 km/h |
| Timișoara | 1,168.1 km/h |
| Brașov | 1,170.2 km/h |
| Constanța | 1,200.8 km/h |
| Craiova | 1,197.9 km/h |
| Sibiu | 1,167.5 km/h |
| Oradea | 1,140.4 km/h |
| Galați | 1,174.8 km/h |
| Chișinău | 1,141.7 km/h |
| London | 1,042.1 km/h |
| Paris | 1,101.6 km/h |
| Madrid | 1,274.7 km/h |
| Rome | 1,246.2 km/h |
| Reykjavik | 730.0 km/h |
| Athens | 1,319.8 km/h |
| Quito | 1,674.4 km/h |
| Singapore | 1,673.9 km/h |
| Nairobi | 1,673.9 km/h |
| New York | 1,269.2 km/h |
| Rio de Janeiro | 1,542.3 km/h |
| Sydney | 1,390.2 km/h |
| Tokyo | 1,360.1 km/h |
The spin is computed from latitude; the other three are background motions, the same for everyone.
Two things are often said about our speed. Both can be checked against the sources above.
Partly true: 1,040 mph at the Equator; the round 1,000 lands near 16 degrees.
At the Equator the spin is 1,674.4 km/h — that is 1,040 mph. The saying rounds the Equator figure.
The round figure of 1,000 mph lands near 16 degrees latitude, north or south. At 45 degrees north it is 1,184 km/h, or 736 mph, and at the poles zero. The further from the Equator, the less true it becomes.
False: a velocity is a size plus a direction.
Added as plain numbers — with the equatorial spin — the four speeds make 629.07 km/s. But the spin axis tilts 23.44° from the orbital axis, the spin changes direction every day, the orbit every year, and the galactic motion and the CMB motion form a 131.5° angle.
629.07 km/s is only the sum of the four magnitudes, each against another frame; it is not your speed in any named frame. Against the CMB, Planck measures the Sun at 369.82 km/s.
The whole galaxy moves against the CMB at 565 km/s, and the Sun's neighbourhood rotates inside the galaxy at 239 — but the two directions form a 151.3° angle, so together they make 373.3 km/s. The direct measurement for the Sun is 369.82 km/s; the gap comes from the Sun's own 17.9 km/s motion. Velocities add like arrows, direction included.
Planck 2018, table 3 · the geometry is this page's computation
Perfectly uniform motion cannot be felt; only accelerations can — changes in the size or direction of velocity. Like a train running straight and smooth: the glass on the table does not tremble.
And the accelerations are tiny. The spin presses you outward at most 0.034 m/s² — 0.35% of your weight, at the Equator; in Bucharest, 0.024 m/s². And the Sun's pull, at 0.006 m/s², is one you fall through together with Earth: all that could be felt is the tidal difference, about 12,000 times smaller. The rest is a smooth ride, billions of years old.
Four questions from the page. The answers are above, sources included.
1 At which latitude do you spin fastest?
2 How fast do you move against the Sun?
3 What do 565 and 239 make when their directions differ?
4 Why do you not feel the speed?
Six questions with answers already published on the page.
Yes — against the CMB, at 1,331,352 km/h. Against Earth's centre, only at your place's spin. Both are true at once; the frame of reference decides.
Because velocities have directions. The galactic motion and the CMB motion form a 131.5° angle, and the spin and the orbit change direction daily and yearly. 629.07 km/s is only the sum of the four magnitudes — with the equatorial spin — not your speed in any named frame.
1,040 mph at the Equator, and the round 1,000 lands near 16 degrees; at 45 degrees north it is 736 mph, and at the poles zero.
Because the motion is uniform, and the accelerations are tiny: the spin presses you with at most 0.35% of your weight, and the Sun's pull is one you fall through with Earth. Uniform motion cannot be felt.
All four, each against its frame: there is no frame-independent speed. The CMB is just the handiest cosmic yardstick.
One full circuit of the Sun around the centre of the galaxy takes about 220 million years, at 229 km/s; at 240 it would be 208.
The spin is computed from the NASA sheet's equatorial radius (6,378.137 km) and sidereal day (23.9345 hours): 2πR·cosine(latitude)/T. Earth is treated as a sphere; the ellipsoid correction is under 0.3% and was not applied.
The orbit (29.78 km/s, between 29.29 and 30.29), the axial tilt (23.44°) and surface gravity come from the same NASA sheet. The working circular speed is 229 km/s (Eilers et al. 2019: formal ±0.2, systematics 2–5%), with 240 (±8) km/s (Reid et al. 2014) beside it; the Sun adds its own 17.9 (±2.0) km/s motion against its neighbourhood (Planck 2018, table 3). The CMB speed, 369.82 km/s, and the directions are also from Planck 2018.
The equivalents are this page's arithmetic, with inputs named: the speed of sound (1,225.1 km/h) from the ideal-gas formula for dry air at 15 °C; light-speed fractions with 299,792,458 m/s exact (NIST); Equator circuits with the 40,075.0 km circumference; the galactic year with 8.122 kpc; the tidal ratio with the 149.598-million-km Sun–Earth distance.
The angles (131.5° and 151.3°) and the vector composition (565 with 239 gives 373.3, against 369.82 measured directly for the Sun) are this page's geometry from Planck's published directions. The 3.5 km/s gap sits inside the two inputs' margins and the Sun's motion against its neighbourhood. The accelerations (0.034 and 0.024 m/s², 0.017 vertical in Bucharest) are also this page's arithmetic, from the NASA sheet's radius and sidereal day.
The 24 places' coordinates were checked against Nominatim (OpenStreetMap) on 3 October 2026: all within 0.3 degrees of our gazetteer.
The cosmic microwave background was released about 380,000 years after the Big Bang (NASA) — which is why the page calls it “the oldest observable light”. Also this page's computation: the latitude where the spin makes 1,000 mph is 16.0 degrees.
The neighbouring chapter about the speed of sound lives at viteza-sunetului.
The neighbouring chapter: viteza-sunetului.
All links were checked at publication.