Pool Chemistry Calculator
All the numbers your pool needs, on one page.
No app needed — everything runs in your browser.
Pick Your Calculator
Pool Volume Calculator
Find your pool size before calculating any chemical dose.
Pool Shock Calculator
Calculate a shock dose based on chlorine and CYA readings.
Pool Chlorine Calculator
Find your routine chlorine dose for the product you use.
Pool pH Calculator
Estimate soda ash or muriatic acid for your target pH.
Pool Alkalinity Calculator
Estimate baking soda or acid to adjust alkalinity.
Pool Stabilizer Calculator
Calculate CYA additions for sun protection.
Pool Salt Calculator
Find the salt dose for your salt chlorine generator.
Ideal Pool Chemistry Ranges
A quick pool chemistry cheat sheet. These are common residential targets; equipment, pool surfaces, stabilizer levels and product labels may call for different ranges.
| Reading | Ideal range | Below range | Above range | Calculator |
|---|---|---|---|---|
| pH | 7.4–7.6 | Corrosion and irritation | Scale; chlorine works less effectively | Pool pH Calculator |
| Free chlorine | 1–3 ppm | Sanitizer may not control contaminants | Irritation; keep swimmers out if above label limits | Pool Chlorine Calculator |
| Total alkalinity | 80–120 ppm | pH can swing quickly | pH harder to adjust; scale risk | Pool Alkalinity Calculator |
| Cyanuric acid (CYA / stabilizer) | 30–50 ppm | Sunlight breaks down chlorine faster | Chlorine needs a higher effective target | Pool Stabilizer Calculator |
| Calcium hardness | 200–400 ppm | Plaster can etch; water becomes aggressive | Scaling and cloudy water | Pool Volume Calculator* |
| Salt (salt pools only) | 2,700–3,400 ppm | Salt cell may stop generating chlorine | Salt cell may shut down; corrosion risk | Pool Salt Calculator |
| Combined chlorine | < 0.5 ppm | Low is desirable | Chloramine odor and irritation; investigate | Pool Shock Calculator |
*No calcium-hardness dose calculator is available yet. Use pool volume as a starting input and follow your calcium product label. A low combined-chlorine reading is normal. For salt, follow your generator manual.
How Pool Chemistry Works
Total alkalinity buffers pH: when alkalinity swings, pH is harder to keep stable. Higher pH reduces the fraction of chlorine in its more active form. CYA protects chlorine from sunlight, but excessive CYA means you need more free chlorine for effective sanitation. Test these four readings first: pH, total alkalinity, free chlorine and CYA, then choose the calculator for the number that needs correcting.
Pool Chemistry Chart
| Reading | Suggested testing frequency | Quick check |
|---|---|---|
| pH and free chlorine | At least weekly; more often with heavy use | Check pH and sanitizer before adjusting either. |
| Total alkalinity | Every two weeks | Recheck if pH keeps drifting. |
| CYA and calcium hardness | Monthly | Recheck CYA after refill or stabilized-chlorine use. |
| Full chemistry panel | At opening and closing | Test everything before seasonal dosing. |
Test more often during heavy use, after storms or chemical additions, and according to local health rules for public pools.
Common Pool Chemistry Problems
pH keeps rising
Test: Test pH and alkalinity.
Next: Check for high alkalinity and aeration from returns or water features.
Calculate the dose: Pool pH Calculator
Cloudy water
Test: Test free chlorine, pH and alkalinity.
Next: Correct sanitizer and water balance; check filtration too.
Calculate the dose: Pool Alkalinity Calculator · Pool Chlorine Calculator
Chlorine not holding
Test: Test free chlorine and CYA.
Next: Check whether CYA is too low or too high before adding more chlorine.
Calculate the dose: Pool Stabilizer Calculator
Alkalinity too high
Test: Test alkalinity and pH.
Next: Use acid in stages, then aerate to bring pH back up.
Calculate the dose: Pool Alkalinity Calculator
Salt cell reading low
Test: Confirm salt with an independent test.
Next: Check the cell and water temperature before dosing salt.
Calculate the dose: Pool Salt Calculator
Frequently Asked Questions
What is a pool chemistry calculator?
A pool chemistry calculator uses your pool volume and test readings to estimate a chemical dose. Pick the calculator for the reading you need to adjust.
What should my pool chemistry levels be?
Start with pH 7.4–7.6, free chlorine 1–3 ppm, total alkalinity 80–120 ppm and CYA 30–50 ppm. Check your equipment and product labels because recommended ranges can vary.
Is there a free pool chemistry calculator?
Yes. All seven calculators on this page are free to use in your browser.
Does this work for above ground pools?
Yes. Measure the above ground pool volume first, then enter it and your test results in the relevant calculator.
Do I need an app for this?
No. Everything runs in your browser; there is no app to download.
Can I use one calculator for everything?
No single dose works for every chemical. Use the volume calculator first, then choose the separate chlorine, shock, pH, alkalinity, stabilizer or salt calculator for your reading.