pOH Calculator

Enter pH or ion data, then compute pOH. Supports custom pKw and scientific notation inputs. Export results to CSV or PDF for reporting easily.

Calculator Inputs

Choose the type of data you have.
Use 14 for ~25°C, or set your value.
This label appears in exports.
Typically 0–14, but may vary.
Calculated from hydroxide activity.
Must be > 0. Supports scientific notation.
Must be > 0. Supports scientific notation.

Example Data Table

Input Mode Input pKw Output pOH Output pH Status
Known pH pH = 9.50 14.00 4.50 9.50 Basic
Known pOH pOH = 3.20 14.00 3.20 10.80 Basic
Known [OH-] [OH-] = 1.0e-5 mol/L 14.00 5.00 9.00 Basic
Known [H+] [H+] = 3.2e-4 mol/L 14.00 10.51 3.49 Acidic
Check pH = 7.00, pOH = 7.00 14.00 7.00 7.00 Neutral

Formula Used

Note: This tool uses common textbook relations and treats inputs as concentrations for practical lab estimation.

How to Use This Calculator

  1. Select your Input mode (pH, pOH, [OH−], [H+], or a consistency check).
  2. Enter pKw if you need a non-default condition.
  3. Provide the required value using normal or scientific notation.
  4. Click Calculate. Results appear above the form.
  5. Use Download CSV or Download PDF to export the results.

Related Calculators

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.