Osmotic Pressure Calculator
Calculate osmotic pressure with the van't Hoff equation (Π = iMRT) from molarity, temperature and the van't Hoff factor. Results in atm, kPa, bar, mmHg and psi.
Input
Output
| Unit | Value |
|---|---|
| No data yet | |
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/osmotic-pressure-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"molarity": "0.1",
"temperature": "25",
"tempUnit": "c",
"vantHoff": "1"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `osmotic-pressure-calculator` tool (Osmotic Pressure Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/osmotic-pressure-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Osmotic Pressure Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
The Osmotic Pressure Calculator applies the van't Hoff equation, Π = i · M · R · T, to find the pressure needed to stop solvent flowing through a semipermeable membrane into a solution.
How to use it
- Enter the solution's molarity (mol/L).
- Enter the temperature and choose Celsius, Kelvin or Fahrenheit.
- Enter the van't Hoff factor i: 1 for non-electrolytes such as glucose or sucrose, about 2 for NaCl, about 3 for CaCl₂.
The result is shown in atmospheres, kilopascals, bar, mmHg and psi, using R = 0.082057 L·atm/(mol·K).
Notes
The equation is accurate for dilute solutions. Concentrated or strongly interacting solutes deviate, and real electrolytes have an effective i slightly below the ideal integer. Human blood plasma, at roughly 0.3 osmol/L and 37 °C, sits near 7.6 atm.