Pool & Hot Tub Chemical Calculators

Know exactly how much to add — in ounces, cups, or teaspoons. Free, brand-neutral, built for beginners.

No sign-up · No chemical brands pushed · Works on your phone

Hot tub — peak season right now

Hot Tub Chemical Calculator

Chlorine or bromine dose in teaspoons.

Hot Tub Volume & Drain Schedule

Find your gallons and when to drain.

Start here

Pool Volume

Find your gallons — the number every other calculator needs.

All-in-One Water Test

Enter your full test, get a sequenced fix.

Sanitizer

Chlorine

Liquid, cal-hypo, dichlor, or trichlor — exact dose.

Pool Shock

Shock level based on your CYA.

Salt

Salt to add, or how much to dilute.

Stabilizer (CYA)

Raise CYA, or dilute if it's too high.

Balance

Acid to lower, soda ash/borax to raise.

Alkalinity

Bicarbonate dose to hit your target TA.

Calcium Hardness

CaCl2 dose for plaster, vinyl, or fiberglass.

LSI / Water Balance

Is your water corrosive or scale-forming?

Brand-neutral

We don't sell chemicals — enter what you have.

Right order & wait times

What to add first, and when to retest.

Made for beginners

Clear language, not just numbers.

Curious how the math works? See how our calculators work.

Save your tests, get reminders, and scan test strips with AI.