pH Calculator (pH, pOH, H+ and OH-)
Science ToolsConvert between pH, pOH, [H+] and [OH-]
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All history →pH Calculator (pH, pOH, H+ and OH-) — at a glance
Enter one value and get all four.
pH = 3
Calculate
[H+] = 0.001 mol/L
Acidic
How to use it — step by step
Just your input — nothing to install or sign up for.
1
Enter your values
Fill in the boxes. Sample values are already there so you can see how it works.
2
Calculate
Press the button to get your answer instantly.
3
Read the result
The main answer is shown in a large card with extra details below it.
4
Copy it
Use the copy button to save the result anywhere.
Pro tips
Small things that make the result better.
✦At 25 °C, pH + pOH = 14.
✦Concentrations are in mol/L, for example 1e-7 for neutral water.
Quick facts
Freeno signup, no limit
Instantresult in a moment
Privatenothing is uploaded
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Frequently Asked Questions
Is my data safe?+
Yes. Everything runs inside your own browser. Your text, files and images are never uploaded to any server.
Is this tool really free?+
Yes — completely free, no signup, no watermark and no usage limit.
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