CST refers to lungs and thoracic cage.
PST TLC is the static recoil pressure at total lung capacity (20-30cmH2O).
85% to 95% of airway resistance is from large airways.
RL refers to pulmonary resistance at FRC (2.0 cmH2O/L/s).

If the figure obtained by the subtraction of the plateau or peak pressure minus PEEP is = 0 (or negative), MediCalculator™ will return an "Incorrect Calculation" message.

Compliance = Volume/Pressure.