pH Calculator

pH from [H⁺] and reverse — with pOH, [OH⁻] and temperature.

100% private — no uploads Free & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use pH Calculator

Follow these steps — everything happens instantly in your browser.

  1. 1

    Step 1. Pick a mode: '[H⁺] → pH' or 'pH → [H⁺]'.

  2. 2

    Step 2. Enter the value (e.g. 1e-7 mol/L for [H⁺], or 7.0 for pH).

  3. 3

    Step 3. Optionally adjust the temperature (default 25 °C) to update Kw.

  4. 4

    Step 4. See pH, pOH, [H⁺], [OH⁻] and the pH scale indicator update instantly.

Why use this tool

Private by design

All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.

Instant

No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.

Free & unlimited

No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.

Works everywhere

Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.

Frequently asked questions

Everything you might want to know about ph calculator.

Want to learn more?

Read our complete pH Calculator tutorial with tips, use cases, and FAQs.