Math and Science
pH Calculator
pH Calculator calculate pH, pOH, hydrogen-ion concentration, and hydroxide-ion concentration at 25 degrees Celsius.
Math and Science
pH Calculator
Calculate pH, pOH, hydrogen-ion concentration, and hydroxide-ion concentration at 25 degrees Celsius.
Formula
pH=-log10[H+], pOH=-log10[OH-], and pH+pOH=14 at 25 C.
About the pH Calculator
Calculate pH, pOH, hydrogen-ion concentration, and hydroxide-ion concentration at 25 degrees Celsius. This tool keeps the requested measurements separate and applies the named method instead of substituting an unrelated general estimate.
How the pH Calculator Works
Enter either hydrogen-ion or hydroxide-ion molarity; the complementary concentration is found from Kw = 1.0 x 10^-14.
Formula
pH=-log10[H+], pOH=-log10[OH-], and pH+pOH=14 at 25 C.
The calculation runs in your browser. Values are validated for required ranges, compatible units, and method-specific restrictions before results are displayed.
Required Inputs
- Known concentration (required).
- Ion concentration (required) - enter in mol/L.
Results Reported
The result panel reports the final answer and the intermediate quantities needed to check the calculation:
- pH
- pOH
- Hydrogen concentration (mol/L)
- Hydroxide concentration (mol/L)
pH Calculator Example
Select Example Data in the calculator to load this reproducible input set:
| Input | Example value |
|---|---|
| Known concentration | hydrogen |
| Ion concentration | 0.0001 mol/L |
How to Use the Calculator
- Confirm that the calculator title and formula match the quantity you need.
- Enter every required value using the unit shown with its field.
- Select Example Data to inspect a valid input set, or enter your own values and select Calculate.
- Review all reported values and the displayed formula before using the answer.
- Use Copy Result or Download CSV when you need a reusable record.
Accuracy and Limitations
The pH+pOH=14 relation is temperature-dependent and concentration is only an approximation to activity in non-ideal solutions.
Keep units consistent, use measurements that represent the actual situation, retain full precision during the calculation, and round only the final answer. Professional decisions may require current official rules, field measurements, laboratory methods, or specialist review.
Frequently Asked Questions
What does the pH Calculator calculate?
Calculate pH, pOH, hydrogen-ion concentration, and hydroxide-ion concentration at 25 degrees Celsius.
Which formula does the pH Calculator use?
pH=-log10[H+], pOH=-log10[OH-], and pH+pOH=14 at 25 C. Enter either hydrogen-ion or hydroxide-ion molarity; the complementary concentration is found from Kw = 1.0 x 10^-14.
How should I use the pH Calculator result?
The pH+pOH=14 relation is temperature-dependent and concentration is only an approximation to activity in non-ideal solutions.