Air Properties: Temperature, Pressure & Density Calculator

Calculate air density based on temperature and pressure using the standard formula: ρ = 1.325 × P_inHg / T_R, where density is expressed in lb/ft³, pressure in inches of mercury, and temperature in Rankine. Also supports the formula using absolute pressure in psia.

Air Density Calculator

Calculate the density of air based on temperature and pressure conditions.

Formula

ρ = 1.325 × P_inHg / T_R

Where:

  • ρ = density (lb/ft³)
  • P_inHg = absolute pressure (inches Hg)
  • T_R = absolute temperature (Rankine)

Alternative formula: ρ = 2.7 × (P_psig + 14.7) / (T_F + 459.7)

Where:

  • P_psig = gauge pressure (psig)
  • T_F = temperature (°F)
Calculator

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Results

Air Density-- lb/ft³
Calculator

Inputs

Results

Air Density-- lb/ft³

Example Calculation

For air at 29.92 inches Hg and 100°F:

ρ = 1.325 × 29.92 / (100 + 459.7) ρ = 1.325 × 29.92 / 559.7 ρ ≈ 0.0708 lb/ft³

Weight of 10 ft³ of air: W = 10 ft³ × 0.0708 lb/ft³ ≈ 0.708 lb