How to use it
- Look at the orange line on the globe: the Tropic of Capricorn. The dashed grey line is the Equator.
- Type a place or press My location to see how far you are from it.
- Read the countries it crosses and the facts.
5 practical uses
- Find the southern limit of the tropics.
- Plan a visit to a tropic marker in Brazil, Australia or Namibia.
- Teach the December solstice.
- Check how far a place is from the tropics.
- See which countries the line crosses.
The maths behind it
The tropic is the parallel at φ = −ε, the negative obliquity of the ecliptic, 23.4365° in 2026, decreasing by about 0.47″ a year. Its length is 2πR cos ε = 36,788 km. The distance from a place to it along the meridian is R·|φ + ε|. The countries crossed are found by testing every edge of every outline for a crossing of that latitude.
What it is
The Tropic of Capricorn is the parallel at about 23°26′S, the mirror of the Tropic of Cancer. The sun stands directly overhead here at noon on the December solstice, and never farther south. South of it the midday sun is always to the north. Between the two tropics is the tropical zone, about 40 % of the Earth's surface, home to a third of its people.
Where it runs
Much less of it is over land than of its northern twin: it crosses Chile, Argentina, Paraguay and Brazil (through São Paulo's northern suburbs); Namibia, Botswana, South Africa, Mozambique and Madagascar; and Australia, passing near Alice Springs and through Rockhampton in Queensland. The rest is the South Pacific, Atlantic and Indian Oceans.
It moves
Like the Tropic of Cancer it drifts as the Earth's tilt changes, currently about 14 m a year towards the Equator.