What is the approximate atmospheric pressure at Mars’s surface?

The average atmospheric pressure at Mars’s surface is about 0.6 kilopascals.

That pressure is less than one percent of Earth’s average sea-level pressure, which is about 101.3 kilopascals. Mars’s atmosphere is thin because the planet has lower gravity and lost much of its original atmosphere over geological time.

Carbon dioxide makes up most of the remaining gas, with smaller amounts of nitrogen and argon. The thin atmosphere cannot support human breathing and provides limited protection from radiation or extreme temperature changes.

Surface pressure varies with altitude, weather, and the seasonal freezing and sublimation of carbon dioxide at the polar regions. It is therefore an average rather than one universal reading everywhere on Mars.