pH of Indicator Calculator

Calculate the pH of an indicator solution using the Henderson–Hasselbalch equation:
$pH = p K_{i n} + \log (\frac{[{In}^{-}]}{[HIn]})$

* Enter the indicator's pK₍in₎ and the ratio [In⁻]/[HIn].

Step 1: Enter Indicator Parameters

Indicator pK_in:

Example: 7.00 (typical for many indicators)

Ratio

[{In}^{-}] / [HIn]

Example: 1 (equal amounts give pH = pK_in)