Calculator

Water Purification Calculator

Calculate bleach or treatment dosage for safe drinking water

Inputs

Bleach dosage (6%)

1 gallon clear8 drops
1 gallon cloudy16 drops
5 gallons clear40 drops (~½ tsp)
55 gallons1 tablespoon

Wait times

Clear water30 minutes
Cloudy water60 minutes
Cold water (<60°F)60 minutes

Boiling guidelines

Sea level1 minute rolling boil
3,000-6,500 ft2 minutes
Above 6,500 ft3 minutes

How to use this calculator

  1. 1Enter the amount of water you need to treat
  2. 2Select your purification method (bleach, iodine, or boiling)
  3. 3Indicate if the water is clear or cloudy
  4. 4Follow the calculated dosage and wait times

Emergency water treatment

Bleach: Use only plain, unscented household bleach (sodium hypochlorite). Scented or color-safe bleach should not be used.

Wait time: Let treated water stand for 30 minutes before drinking. If water is cloudy, double the dosage and wait 60 minutes.

Boiling: The most reliable method. Bring water to a rolling boil for 1 minute (3 minutes above 6,500 ft elevation). This kills all pathogens but doesn't remove chemical contamination.

Frequently asked questions

What type of bleach should I use?

Use only plain, unscented household bleach containing sodium hypochlorite. Do not use scented, color-safe, or bleach with added cleaners. Check the label for 6% or 8.25% sodium hypochlorite.

How do I know if water is purified?

After treatment, water should have a slight chlorine smell. If you don't smell chlorine after 30 minutes, repeat the treatment. The chlorine smell indicates active disinfection.

What about filtering before treatment?

If water is cloudy, filter it through clean cloth, coffee filters, or let sediment settle first. Clear water purifies more effectively. Double the bleach dose for cloudy water.

Result

40.0drops

Use plain unscented bleach only

Details

Approx. Teaspoons0.53tsp
Wait Time30.0minutes