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Water Potential of a Solution Calculator

💧 Diffusion, osmosis & transport. Use the Water potential of a solution formula to find water potential ψ, solute potential ψs, pressure potential ψp: pick the value you want, type the others, and the answer updates as you go.

ψ=ψs+ψp\psi = \psi_s + \psi_p

Solute potential (always negative) plus pressure potential.

Water potential ψ-500 kPa

Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.

What each letter means

QuantityUnit
Water potential ψkPa
Solute potential ψskPa
Pressure potential ψpkPa

Worked example

Find the water potential ψ when Solute potential ψs = -800 kPa, Pressure potential ψp = 300 kPa.

Using = +: Water potential ψ = -500 kPa.

Frequently asked questions

What is the formula for Water potential of a solution?

= +. Solute potential (always negative) plus pressure potential.

What do the letters stand for, and what units are used?

Water potential ψ in kPa, Solute potential ψs in kPa, Pressure potential ψp in kPa.

How do you calculate water potential ψ?

Put the values into = +. For example, with Solute potential ψs = -800 kPa, Pressure potential ψp = 300 kPa, water potential ψ = -500 kPa.

Can I solve for a different value?

Yes. In the calculator above, pick the circle next to any value (water potential ψ, solute potential ψs, pressure potential ψp) and fill in the others: it rearranges the formula for you.

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