Ammonia Toxicity Calculator

Calculate the toxic ammonia (NH3) fraction from total ammonia, pH, and temperature.

Results

Visualization

How It Works

Total ammonia exists as toxic NH3 (free ammonia) and safer NH4+ (ammonium). The ratio depends on pH and temperature — higher pH and temperature mean more toxic NH3. At pH 7.0 and 77°F, only about 0.5% is toxic NH3. At pH 8.0, that jumps to about 5%. This is why pH matters so much during fish-in cycling.