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Pool Chemical Calculator

gal
ppm
ppm
Chlorine Needed
0 oz
pH Adjustment
0 oz
Chemical Type
Alkalinity Adjuster
0 lbs
Show the math
Enter values to see the worked formula.

What Your Result Means

How This Calculator Works

You enter your pool volume in gallons, the current and target chlorine levels in ppm, and the current and target pH. The tool applies standard dosing factors — 0.0073 oz of liquid chlorine per gallon per ppm for chlorine, and 0.0013 oz per gallon per 0.1 pH unit for pH adjustment. Alkalinity dosing assumes a fixed rate of 1.2 lbs of baking soda per 10,000 gallons per 10 ppm increase. Results are estimates; always retest after adding chemicals.

Quick Questions

What is the ideal chlorine level for a residential pool?

Most health departments recommend 1–3 ppm of free chlorine for residential pools. Higher levels (up to 5 ppm) are safe for swimming but may cause eye irritation. Levels below 1 ppm are generally too low to sanitize effectively.

Should I adjust pH or chlorine first?

Adjust pH first. Chlorine works most effectively in the 7.2–7.6 pH range. If pH is too high, chlorine loses much of its sanitizing power, so any chlorine you add will be partially wasted.

How do I know my pool volume?

For rectangular pools: length × width × average depth × 7.48 gives gallons. For round pools: diameter × diameter × average depth × 5.9. If you are unsure, check your pool builder's documentation or use a pool volume calculator.

Can I add all the chemicals at once?

No. Add one chemical at a time, run the pump for at least 15–30 minutes, and retest before adding the next. Mixing chemicals in the pool water simultaneously can cause dangerous reactions or cancel each other out.

Sources

Method & review

MethodologyHow we calculate this Reviewed & Updated2026-04 Next review2027-04

Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.