pH Calculator — pH = −log[H⁺]
pH compresses a huge range of acidities into a handy 0–14 scale: each unit is a tenfold change in [H⁺]. Convert either direction between pH and hydrogen-ion concentration.
pH Calculator — pH = −log[H⁺]
How to interpret the result
Worked check: [H⁺] = 1.0×10⁻³ M → pH = 3.00; back again, 10^(−3.00) = 1.0×10⁻³ M. Remember pH is logarithmic — pH 3 is ten times more acidic than pH 4.
Assumptions
- Aqueous solution near 25 °C
- Activity approximated by concentration