Pool Chemical Dose Calculator
Enter your pool size and test results. The calculator estimates how much chemical to add to move from current to target values.
Estimates assume common products: 10% liquid chlorine, 31.45% muriatic acid, soda ash, baking soda, calcium chloride, dry stabilizer, and pool salt.
How this pool chemical calculator helps
Pool care gets easier when you stop guessing. This pool chemical calculator gives fast dosing estimates for the most common water balance adjustments: free chlorine, pH, total alkalinity, calcium hardness, cyanuric acid (stabilizer), and salt. Instead of adding chemicals “by feel,” you can use measured test values and calculate a practical starting dose.
The goal is simple: cleaner water, safer swimming, and fewer swings in chemistry. A stable pool usually costs less to maintain because you avoid over-correcting and wasting product.
Recommended pool chemistry ranges
| Parameter | Typical Range | Why It Matters |
|---|---|---|
| Free Chlorine (FC) | 2–6 ppm | Sanitizes water and prevents algae/bacteria growth. |
| pH | 7.2–7.8 | Comfort, sanitizer efficiency, and equipment protection. |
| Total Alkalinity (TA) | 60–120 ppm | Buffers pH and reduces rapid pH drift. |
| Calcium Hardness (CH) | 150–400 ppm | Protects plaster surfaces; helps avoid scaling/corrosion. |
| Cyanuric Acid (CYA) | 30–60 ppm (non-salt), 60–80 ppm (salt pool) | Protects chlorine from UV sunlight breakdown. |
| Salt | 2700–3600 ppm (check manufacturer) | Needed for salt chlorine generator operation. |
How to use the calculator correctly
1) Start with accurate testing
Use a reliable drop-based test kit for best results. Test strips are convenient, but they can be less precise, especially for pH and alkalinity.
2) Enter current values and realistic targets
Don’t chase extreme numbers. Aim for stable, middle-of-range targets unless your pool surface or equipment requires a specific value.
3) Add chemicals in stages
Large corrections should be split into multiple doses. Circulate the pool, retest, and then adjust again if needed. This lowers the risk of overshooting.
What each adjustment means
Free chlorine
If FC is low, sanitation drops and algae risk rises. The calculator estimates liquid chlorine needed to raise FC. If FC is above target, typically allow sunlight and normal demand to bring it down naturally.
pH
High pH can reduce chlorine effectiveness and promote scale. Low pH can be corrosive and irritating. This calculator estimates muriatic acid to lower pH or soda ash to raise it.
Total alkalinity
TA acts like a pH stabilizer. Low TA often leads to pH bounce. High TA can push pH upward over time. Use baking soda to raise TA; lowering TA usually involves acid plus aeration.
Calcium hardness
CH matters most for plaster and concrete pools. Low CH can be aggressive to surfaces; high CH increases scale risk. Calcium chloride is commonly used to increase CH.
Cyanuric acid
CYA protects chlorine from UV loss. Too little CYA means chlorine burns off quickly in sunlight. Too much CYA can make chlorine less effective, requiring higher FC levels.
Practical maintenance tips
- Run pump long enough for full circulation before retesting (often 30–60+ minutes after dosing).
- Retest pH and chlorine frequently in hot weather and after heavy swimmer load.
- Keep records of test readings and chemical additions to spot trends.
- Brush and vacuum routinely—chemistry and physical cleaning work together.
- If numbers are far off, correct one or two parameters at a time.
Important note on precision
Any calculator is an estimate because real pool conditions vary (water temperature, product purity, existing dissolved solids, and test accuracy). Use these outputs as a starting point, then retest and fine-tune.