Education & Student
pH Calculator
pH — it computes pH = −log₁₀[H⁺] (and pOH = 14 − pH) from the hydrogen-ion concentration. This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
pH Calculator helps you work out pH. Enter your input type and value and it returns the pH (or hydrogen-ion concentration) instantly, right in your browser with nothing uploaded.
About this calculator
It computes pH = −log₁₀[H⁺] (and pOH = 14 − pH) from the hydrogen-ion concentration. That is the whole of the calculation — the mistakes happen in the inputs. It matters when grades, percentages or averages decide a next step and hand arithmetic is error-prone. Worked example: A solution with [H⁺] = 1 × 10⁻³ M has pH = −log₁₀(10⁻³) = 3 (acidic). Use the calculator with your own figures; it runs entirely on your device.
How to use
- Choose the input type: H⁺, OH⁻, pH, or pOH.
- Enter the value (for example 1e-7).
- Press Calculate to find the pH.
- Read the pH, pOH, and concentrations.
Why use pH Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard formulas for quick educational estimates; check critical results before relying on them.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for quick what-if calculations
Use it for verifying a textbook result
Use it when checking a homework answer
Use it before a practical assessment
Use it when teaching a science concept
Use it when comparing two scenarios
Technical notes
pH Calculator computes pH = −log₁₀[H⁺] (and pOH = 14 − pH) from the hydrogen-ion concentration.
Results assume ideal conditions and consistent units, so convert your inputs to the units shown before calculating.
All arithmetic runs in your browser using double-precision floating point, so extreme inputs may show tiny rounding differences.
FAQ
Can I enter pH instead of concentration?
Yes. You can start from H⁺ or OH⁻ concentration, or from a pH or pOH value, and the rest are calculated.
How are pH and pOH related?
At 25°C they add up to 14, so pOH = 14 − pH.
Why must concentration be positive?
pH uses the logarithm of concentration, which is only defined for values greater than zero.
Does the pH Calculator send my data to a server?
No. The pH Calculator runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
A solution with [H⁺] = 1 × 10⁻³ M has pH = −log₁₀(10⁻³) = 3 (acidic).