pH, pOH and Hydrogen Ion Concentration Made Simple

You know the pH of your pool water is 7.4 and you want to know if that's actually fine. Or you're working a homework problem that gives you a hydrogen ion concentration of 3.2 × 10⁻⁵ M and asks for the pH. Either way, you need a quick way to convert between these values without fumbling with logarithms.

Slide the scale, see everything

The pH calculator gives you a single slider or input. Move it to any pH value and you instantly see the pOH, the hydrogen ion concentration [H⁺], and the hydroxide ion concentration [OH⁻]. All four values update together because they're mathematically linked — pH + pOH = 14 at 25°C, and [H⁺] = 10⁻ᵖᴴ.

There's also a reference strip showing where common substances fall. Battery acid sits near pH 1, lemon juice around 2, coffee around 5, pure water at 7, baking soda around 9, bleach around 13. It's useful for building intuition about what the numbers actually mean in the real world.

When you'd use this

If you're preparing buffer solutions in a lab, you often need to target a specific pH and then calculate the corresponding ion concentrations to figure out how much acid or base to add. The pH calculator saves you from typing log expressions into a separate calculator.

Students studying acid-base chemistry can use it to verify their work. If your textbook says a 0.01 M HCl solution has pH 2, you can punch in pH 2 and confirm that [H⁺] = 0.01 M. It builds confidence in the relationships between the values.

For the next step — figuring out how to actually prepare that solution — the dilution calculator handles the C₁V₁ = C₂V₂ math.