Free tool
Pool Chemical Calculator
Every pool chemical dose in one place. Enter your volume and test readings once and get an exact, in-order dosing plan — chlorine, pH, alkalinity, calcium, stabilizer, and salt.
How to use this calculator
- 1Enter your pool volume
Type your pool's gallons. Don't know it? Use the Pool Volume Calculator first — every dose scales from this number.
- 2Enter each current reading
From your test strip or kit, fill in the current free chlorine, pH, total alkalinity, calcium hardness, cyanuric acid, and salt.
- 3Set your targets
Sensible targets are pre-filled. Adjust any of them to your own goal (for example, a higher free-chlorine target if your CYA is high).
- 4Read your dosing plan
The calculator lists exactly what to add for each parameter — soda ash, muriatic acid, baking soda, calcium chloride, stabilizer, chlorine, or salt.
Frequently asked
Pool chemical calculator questions
What order should I add pool chemicals?
Balance total alkalinity first, because it buffers pH and makes pH easier to hold. Then adjust pH, then free chlorine, then calcium hardness, cyanuric acid, and salt. Add one chemical at a time, run the pump so it circulates, and retest before dosing again — never dump everything in at once.
What are the ideal pool chemistry levels?
Common residential targets: free chlorine 1-3 ppm (higher if your cyanuric acid is high), pH 7.2-7.6, total alkalinity 80-120 ppm, calcium hardness 200-400 ppm, cyanuric acid 30-50 ppm, and salt 2700-3400 ppm for a saltwater pool. The calculator pre-fills targets in these ranges, but you can change any of them.
Can I use this for a hot tub or spa?
Yes. Enter your spa or hot tub's gallons instead of a pool's and the doses scale down accordingly. Because spa volumes are small, measure carefully — a little chemical moves the numbers a lot — and retest after each addition.
How is each dose calculated?
Every row uses the same standard, widely-published rule-of-thumb dosing figures as Skimmer's individual calculators — for example, one gallon of 12.5% liquid chlorine raises 10,000 gallons by about 10 ppm, and ~1.5 lb of baking soda raises alkalinity ~10 ppm per 10,000 gallons. They're estimates: exact product concentration, temperature, and alkalinity all shift the real result, so always retest.
Can I lower a reading that's too high?
pH and total alkalinity come down with muriatic acid (alkalinity uses the slow "aerate" method). But there's no chemical that removes calcium hardness, cyanuric acid, or salt — the only way to lower those is to drain part of the pool and refill with fresh water. The plan flags which is which.