Pool Ratio

Pool Chemical Calculator

Enter your pool and today’s test results. You get a step-by-step plan: what to add, how much of your product, and in what order.

Last updated · Checked against published product doses · How we calculate

1. Your pool

Pool shape

2. Today's test results

The products you have
Your pool holds
–

3. What to add, in this order

    Add one chemical at a time with the pump running, never mix chemicals, and pre-dissolve granules in a bucket of pool water. Add about ¾ of a dose, circulate 30–60 minutes and retest. Your test kit and the product label have the last word.

    Single-chemical calculators

    Pool Volume CalculatorPool Salt CalculatorPool Chlorine CalculatorPool pH CalculatorPool Shock CalculatorPool Alkalinity CalculatorPool Stabilizer CalculatorPool Calcium Hardness Calculator

    How the plan is ordered

    Chemicals interact, so the order matters. Alkalinity steers how pH behaves, so it goes first. pH comes next, because acid also lowers alkalinity and soda ash raises it. Calcium, stabilizer and salt are slow and stable. Chlorine goes last, ideally in the evening, at a level set by your stabilizer.

    Example: 15,000 gallons, FC 1, pH 7.9, TA 70, CYA 30

    1. Alkalinity 70 is in range: no change.
    2. Lower pH 7.9 → 7.5 with muriatic acid (start with ¾ of the dose, retest).
    3. Raise free chlorine to about 3.5 ppm, the target for CYA 30.

    Your exact amounts appear in the plan above as you type.

    Popular pool sizes

    15 ft round pool: 5300 gal18 ft round pool: 7600 gal24 ft round pool: 13500 gal15 × 30 ft oval pool: 10600 gal18 × 33 ft oval pool: 14000 gal16 × 32 ft pool: 18200 gal18 × 36 ft pool: 23000 gal20 × 40 ft pool: 28400 gal

    Safety first

    Add chemicals one at a time, directly to the pool water with the pump running. Never mix products, never add water to acid, and store chlorine and acid apart. Wear gloves and eye protection. Keep everyone out of the water until chlorine is back in its normal range.

    Frequently asked questions

    What order should I add pool chemicals in?

    Alkalinity first, then pH, then calcium, then stabilizer and salt, and chlorine last. Wait for each one to circulate (about 30 minutes to a few hours) before adding the next, and never mix chemicals together.

    How accurate is this calculator?

    The doses use published product strengths and standard water chemistry, including how alkalinity and stabilizer buffer pH. Test kits and products vary, so add most of a dose, circulate, retest and top up.

    What are the ideal pool chemical levels?

    Typical targets: pH 7.4–7.6, alkalinity 70–90 ppm, calcium 250–450 ppm for plaster (much less for vinyl), stabilizer 30–50 ppm (60–80 for salt pools), and free chlorine about 7.5–11.5% of your stabilizer.

    Can I link to my results?

    Yes. Every field can be set in the address, e.g. /?shape=known&volume=15000&FC=1&pH=7.9&TA=70&CYA=30, so you can bookmark your pool or share it with whoever looks after it.