Air Density Calculator
Estimate dry-air density from absolute pressure and air temperature using the ideal-gas approximation.
How to use this calculator
- Enter absolute pressure in pascals and temperature in degrees Celsius.
- Check that all inputs use the same units, time period and population scope.
- Change one assumption at a time when comparing scenarios.
Formula used by air density calculator calculator
Dry-air density ≈ absolute pressure ÷ (specific gas constant for dry air × absolute temperature), using R ≈ 287.05 J/(kg·K).
- Dry-air density ≈ absolute pressure ÷ (specific gas constant for dry air × absolute temperature), using R ≈ 287.05 J/(kg·K).
- The model treats air as dry and ideal and uses absolute pressure. Humidity, composition and real-gas effects may matter for precision work.
- The tool validates entered values and formats results for readability; it does not verify assumptions against external records.
Worked examples
Worked example
101,325 Pa and 20°C.
101,325 ÷ (287.05 × 293.15) ≈ 1.204 kg/m³.
Estimated dry-air density is about 1.204 kg/m³.
Understanding the result
Estimate dry-air density from absolute pressure and air temperature using the ideal-gas approximation.
The model treats air as dry and ideal and uses absolute pressure. Humidity, composition and real-gas effects may matter for precision work.
Important notes
The model treats air as dry and ideal and uses absolute pressure. Humidity, composition and real-gas effects may matter for precision work.
Treat the result as an estimate based on the entered inputs. For regulated, engineering, employment, tax or business decisions, check applicable official rules, specifications and professional guidance.
Frequently asked questions
Can I enter gauge pressure?
No. Convert gauge pressure to absolute pressure before using this formula.
Does humidity change density?
Yes. This simplified calculator neglects humidity; humid air has a different density at comparable conditions.
How should I use the result?
The model treats air as dry and ideal and uses absolute pressure. Humidity, composition and real-gas effects may matter for precision work.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.