A pool chemical calculator tells you exactly how much chlorine, pH adjuster, alkalinity increaser, and stabilizer to add based on your pool's volume and current water test readings. Enter your numbers below to get precise chemical dosages — no guesswork, no overtreatment. All calculations run in your browser and follow standard pool industry dosing formulas.
Pool Volume
Enter pool dimensions to calculate volume (Length x Width x Avg Depth x 7.5)
Current Water Test Readings
Ideal: 7.4 – 7.6
Ideal: 1 – 3 ppm
Ideal: 80 – 120 ppm
Ideal: 30 – 50 ppm
Ideal Pool Chemistry Ranges
| Parameter | Ideal Range | Acceptable |
|---|---|---|
| Free Chlorine | 1 – 3 ppm | 1 – 5 ppm |
| pH | 7.4 – 7.6 | 7.2 – 7.8 |
| Total Alkalinity | 80 – 120 ppm | 60 – 180 ppm |
| CYA / Stabilizer | 30 – 50 ppm | 30 – 80 ppm |
How to Use the Pool Chemical Calculator
Maintaining balanced pool water chemistry is essential for swimmer safety, equipment longevity, and crystal-clear water. Adding too little chemical leaves your pool vulnerable to algae and bacteria; adding too much wastes money and can irritate skin and eyes. This pool chemical calculator removes the guesswork by computing exact dosages based on your pool's volume and current water test readings.
Step 1: Enter Your Pool Volume
Type your pool volume in gallons directly, or click "Calculate from dimensions" to enter your pool's length, width, and average depth in feet. The calculator multiplies length x width x average depth x 7.5 to convert cubic feet to gallons. For irregularly shaped pools, estimate the average dimensions or calculate each section separately and add them together.
Step 2: Enter Your Current Water Test Readings
Use a pool test kit or test strips to measure your current pH, free chlorine, total alkalinity, and CYA (cyanuric acid / stabilizer). Enter each reading into the corresponding field. The tool shows ideal ranges next to each input so you can immediately see which parameters need adjustment.
Step 3: Set Your Target Levels
Choose your target pH (7.4, 7.5, or 7.6 are ideal) and enter target levels for chlorine, alkalinity, and CYA. The pool chemical calculator uses these targets along with your current readings to compute exactly how much of each chemical you need. If a parameter is already within the ideal range, no chemical will be recommended for that reading.
Step 4: Review Your Chemical Dosages
Click "Calculate Chemical Dosages" to see a clear checklist of what your pool needs. Each chemical is listed with the exact amount in ounces, cups, or pounds — whichever unit is most practical. The tool tells you whether to add soda ash (pH up), muriatic acid (pH down), liquid chlorine, baking soda (alkalinity), or stabilizer. Items already in range are marked with a green checkmark.
Step 5: Add Chemicals Safely
Always add chemicals one at a time with the pool pump running. Adjust total alkalinity first, then pH, then chlorine — this order matters because alkalinity acts as a buffer for pH. Wait at least 4-6 hours between additions and retest the water before adding the next chemical. Never mix pool chemicals together, and always add chemicals to water rather than the reverse.
Frequently Asked Questions
Is this pool chemical calculator free to use?
Yes, this pool chemical calculator is completely free with no signup required. All calculations run locally in your browser — your pool data is never sent to any server. Use it as many times as you need with no limits.
Is my data private when I use this tool?
Absolutely. Every calculation runs entirely in your browser using client-side JavaScript. No pool volumes, chemical readings, or personal information are ever transmitted to a server. Your data stays completely private on your device.
How do I calculate my pool volume in gallons?
Multiply your pool's length by width by average depth (all in feet), then multiply by 7.5 to get gallons. For example, a 30 x 15 ft pool with a 5 ft average depth holds 30 x 15 x 5 x 7.5 = 16,875 gallons. This calculator includes a built-in volume calculator that does the math for you.
What is the ideal pH for a swimming pool?
The ideal pH range for a swimming pool is 7.4 to 7.6. Water below 7.2 is too acidic and can corrode equipment and irritate skin. Water above 7.8 is too alkaline and reduces chlorine effectiveness. Test your pH at least twice per week during swimming season for best results.
How much chlorine should I add to my pool?
The amount depends on your pool volume and current free chlorine level. As a general rule, 10 oz of liquid chlorine (12.5% sodium hypochlorite) raises the free chlorine level by 1 ppm in 10,000 gallons of water. This calculator gives you the exact dosage based on your specific readings.
What does CYA (stabilizer) do in a pool?
Cyanuric acid (CYA), also called stabilizer or conditioner, protects chlorine from being destroyed by sunlight. Without it, UV rays can break down up to 90% of free chlorine within two hours. The ideal CYA range is 30-50 ppm for most residential pools. Too much CYA reduces chlorine effectiveness.
How often should I test my pool water?
Test chlorine and pH at least twice per week during swimming season, and once per week during the off-season. Test alkalinity and CYA once per week. After heavy rain, high bather load, or adding chemicals, retest after the water has circulated for at least 4 hours before making additional adjustments.
Can I add all pool chemicals at the same time?
No, never add multiple chemicals at the same time. Add one chemical, run the pump for at least 4-6 hours, then retest before adding the next. Always adjust alkalinity first, then pH, then chlorine. Adding chemicals simultaneously can cause dangerous reactions and reduce effectiveness.