Water Potential Calculator

Your details

Unit used for all potential inputs and outputs. 1 MPa = 1000 kPa = 10 bar = 9.869 atm.
Choose your solute. The ionization constant (i) is set automatically; use Custom to enter your own.
Molar concentration of the solute in the solution.
mol/L
Solution temperature. Used in the van't Hoff equation.
°C
Turgor or hydrostatic pressure. Positive in turgid cells, negative in xylem under tension. In MPa by default.
MPa
Gravitational potential matters at large height differences (tall trees). Ψg = -g * height (m) / Vm.
Matric potential (Ψm) accounts for water binding to soil particles or cell walls. Always negative or zero.
Enter water potentials of two systems to determine which direction water will move.
Water Potential (Ψ)Significant water stress
-0.9395

Total water potential = sum of all component potentials

Osmotic (Solute) Potential (Ψs)-1.2395
Pressure Potential (Ψp)0.3
UnitMPa
Osmotic (Ψs)-1.2395
Pressure (Ψp)0.3
Gravitational (Ψg)-
Matric (Ψm)-

Total water potential is -0.9395 MPa.

  • Osmotic potential (Ψs) is -1.2395 MPa, always negative because dissolved solutes lower the free energy of water.
  • Pressure potential (Ψp) is 0.3000 MPa, positive turgor pressure that pushes water potential upward - typical of a turgid living cell.
  • Water moves from higher (less negative) to lower (more negative) water potential - osmosis follows the water potential gradient.

Next stepEnable "Compare two systems" to determine the direction water will move between two compartments.

 = Powered by OnlyCalculators