Work out transpiration rate instantly with clear inputs, formula shown and shareable results.
Divides water loss by leaf area and time, and converts to the millimole per square metre per second units used in gas exchange physiology.
Transpiration rate
Rate = water lost / (leaf area x time); mmol/m2/s = (g/m2/h / 18.015) / 3600 x 1000
The vapour pressure deficit between leaf and air, modulated by stomatal conductance and boundary layer resistance.
Around 1 to 5 mmol/m2/s in well-watered plants in daylight, falling to near zero when stomata close.