AeroToolbox Calculators

AeroToolbox combines aviation calculations with aircraft-design and ground-school explanations. Its density-altitude tool takes airfield elevation, local QNH, outside-air temperature and dew point, returning pressure and density altitude. Turning off dew point uses a dry-air approximation, so the two modes represent different humidity assumptions. The guide defines QNH as the altimeter setting giving field elevation on the ground and describes pressure-altitude calculation in feet with QNH converted to mb, equivalent to hPa. Density altitude is the standard-atmosphere altitude corresponding to the calculated air density. Use the explanation for atmospheric comparisons and learning; an aircraft's own performance charts remain the source for its operating limits.