The lift generated by a balloon varies with air pressure and temperature. This page looks at the relationship between pressure and altitude. Formalas for calculating the pressure at an altitude, and for determining the altitude of a nominated pressure level are provided. Online tools are also available for performing pressure and altitude conversions.
Pressure and Altitude Conversions and Calculations
Pressure decreases with Altitude
Air pressure decreases with height in the atmosphere. The air pressure at a given altitude can be calculated using the formula:
Calculating the Altitude of a Known Pressure
You can calculate the altitude above sea level of a site when you know the sea level pressure reading and the absolute pressure of your site. If you use 1013.25 hPa (standard pressure) at sea level then you will calculate pressure height in the International Standard Atmosphere (ISA).
Balloon Pilot and Crew Education – Pressure to Altitude Conversion – Technical data content credited to Mr Steve Griffin