Free tool · 1 min
Pool volume calculator
Gallons and liters for rectangle, round, oval and kidney pools with a shallow and deep end. The formula is shown under the result.
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Free pool tool
Pool chemical calculator
Enter your pool size and test results to get doses of chlorine, acid, baking soda, calcium, stabilizer or salt. Switch to shock mode for a shock dose based on your CYA.
Free, no sign-up. Updated October 14, 2026.
1What do you need?1 of 3
2Your pool2 of 3
Not sure? Calculate your pool volume. The result carries over on this device.
3Test results3 of 3
Results
Doses for 15,000 gallons. Use one product per reading.
Free chlorine
RaiseRaise free chlorine by 3 ppm. Pick one product:
| Product | Amount |
|---|---|
| Liquid chlorine 10% | 58 fl ozabout 7.2 cups |
| Liquid chlorine 12.5% | 46 fl ozabout 5.8 cups |
| Cal-hypo 65%Also adds about 2.1 ppm calcium hardness. | 9.2 ozby weight |
| Cal-hypo 73%Also adds about 2.1 ppm calcium hardness. | 8.2 ozby weight |
| Dichlor (55% granular)Also adds about 2.7 ppm CYA. | 11 ozby weight |
| Trichlor (90% tabs or granules)Also adds about 1.8 ppm CYA. | 6.7 ozby weight |
- Add liquid chlorine in front of a return jet with the pump running.
- Dissolve granular products in a bucket of pool water first. Never mix cal-hypo with trichlor or dichlor.
- Never mix chemicals together, and add chemical to water, never water to chemical.
pH
LowerLower pH by 0.3. Pick one product:
| Product | Amount |
|---|---|
| Muriatic acid 31.45% | 23 fl ozabout 2.88 cups |
| Dry acid (sodium bisulfate) | 1.9 lb31 oz |
- pH doses assume 12.8 fl oz of 31.45% muriatic acid lowers pH about 0.2 in 10,000 gallons at 100 ppm total alkalinity, scaled with your TA. Real results vary from about 0.1 to 0.3, so add half, circulate for 30 minutes and retest.
- Pour acid slowly in front of a return jet with the pump on. Wear gloves and eye protection.
- Acid also lowers total alkalinity a little.
Total alkalinity
On targetTotal alkalinity is already at target. Nothing to add.
Calcium hardness
RaiseRaise calcium hardness by 50 ppm. Pick one product:
| Product | Amount |
|---|---|
| Calcium chloride 77% (flake) | 9 lb144 oz |
| Calcium chloride 94% (anhydrous) | 7.4 lb118 oz |
- Dissolving calcium chloride gets hot. Add it slowly to a bucket of pool water, never water onto the chemical.
- Add in stages: put in about half, run the pump at least 30 minutes, retest, then add the rest if needed.
Cyanuric acid (stabilizer)
RaiseRaise CYA by 10 ppm.
| Product | Amount |
|---|---|
| Cyanuric acid (stabilizer granules) | 1.3 lb20 oz |
- Granular CYA dissolves slowly. Put it in a sock in front of a return or in the skimmer basket, and do not backwash for 2 to 3 days.
- Retest after 5 to 7 days; it takes that long to fully register.
Add in stages, retest
Adjust one reading at a time: alkalinity, then pH, calcium, stabilizer and chlorine last. Add chemicals to water, never water to chemicals, and never mix products. Put in about half, run the pump 30 minutes, retest, then finish.
How it works
Every dose is a 10,000 gallon rate, scaled to your pool.
These are the reference amounts the calculator uses, and the order to apply them in.
How to use the calculator
Start with an accurate volume. The pool volume calculator works it out, and this page picks up the result on the same device. Test with a drop-based kit or reliable strips, enter the readings under Current, and set Target to where you want each one. Each reading gets a card listing the amount for every common product. Use one product per reading.
Liquids are shown in fluid ounces and cups, switching to gallons for large doses. Dry products are in ounces and pounds by weight. Weigh dry chemicals on a kitchen or postal scale, because a scoop of cal-hypo and a scoop of baking soda weigh different amounts.
Reference doses per 10,000 gallons
- Liquid chlorine: 1 gallon of 12.5% raises free chlorine about 12.5 ppm. 10% raises it about 10 ppm.
- Cal-hypo: 1 lb of 65% raises FC about 7.8 ppm, and 73% about 8.7 ppm. Each 1 ppm of FC also adds about 0.7 ppm calcium hardness.
- Dichlor and trichlor: 1 lb of dichlor raises FC about 6.6 ppm and trichlor about 10.8 ppm. They add about 0.9 ppm and 0.6 ppm of CYA for every 1 ppm of chlorine.
- Muriatic acid (31.45%): about 25.6 fl oz lowers total alkalinity 10 ppm. One pound of dry acid does the work of about 12 fl oz of muriatic acid.
- Baking soda: about 1.4 lb raises total alkalinity 10 ppm.
- Calcium chloride: about 1.2 lb of 77% flake raises calcium hardness 10 ppm.
- Cyanuric acid: about 13.4 oz raises CYA 10 ppm.
- Pool salt: about 83.5 lb raises salt 1,000 ppm.
pH assumption: pH doses assume 12.8 fl oz of 31.45% muriatic acid lowers pH about 0.2 in 10,000 gallons at 100 ppm total alkalinity, scaled with your TA. Real results vary from about 0.1 to 0.3, so add half, circulate for 30 minutes and retest. Alkalinity, stabilizer and borates all change how far each ounce of acid moves pH, so the pH dose is an estimate.
Shocking your pool
Stabilizer (CYA) protects chlorine from sunlight and also slows it down, so higher CYA needs higher free chlorine to kill algae. The shock level is about 40% of CYA: 12 ppm at 30 CYA, 16 ppm at 40 CYA, 20 ppm at 50 CYA. Unstabilized pools get a 10 ppm minimum.
Hold chlorine at the shock level, retesting every few hours and topping up, until the water is clear, combined chlorine reads 0.5 ppm or less, and the pool loses no more than 1 ppm overnight. Use liquid chlorine or cal-hypo. Dichlor and trichlor add stabilizer each time, which raises the next shock level.
When chemicals can't fix it
CYA, calcium and salt stay in the water until it is replaced. When a target is below the current reading, the calculator shows the share of water to drain and refill, assuming the fill water contains none of that chemical. Draining 25% of the water lowers each of them by about 25%.
Safety
- Add chemicals to water, never water to chemicals, and never mix two products.
- Pour liquids in front of a return jet with the pump running. Pre-dissolve granular products in a bucket.
- Wear gloves and eye protection for acid and chlorine, and store the two apart.
- Follow the product label when it disagrees with the calculator. Strength varies by brand and age.
Instant estimate
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FAQ
Questions? Glad you asked.
How much liquid chlorine do I add to my pool?
One gallon of 12.5% liquid chlorine raises free chlorine by about 12.5 ppm in 10,000 gallons (10% bleach raises it about 10 ppm). To raise a 20,000 gallon pool by 2 ppm you need 2 ÷ 12.5 × 2 = 0.32 gallons, or about 41 fl oz of 12.5% liquid chlorine.
How much shock do I need?
A common rule of thumb is to shock to a free chlorine level of about 40% of your cyanuric acid (CYA), with at least 10 ppm in unstabilized water. At 40 ppm CYA that is 16 ppm FC. Hold that level, topping up as needed, until the water is clear and overnight chlorine loss is 1 ppm or less.
How much muriatic acid lowers pH?
As a starting point, about 12.8 fl oz of 31.45% muriatic acid lowers pH by roughly 0.2 in 10,000 gallons at 100 ppm total alkalinity. Higher alkalinity needs more acid and lower alkalinity needs less, and real results range from about 0.1 to 0.3, so add half, circulate for 30 minutes and retest.
How much baking soda raises alkalinity?
About 1.4 to 1.5 lb of baking soda raises total alkalinity by 10 ppm in 10,000 gallons. Broadcast it over the surface with the pump running and retest after a few hours.
Which order should I adjust pool chemicals in?
Alkalinity first, because it buffers pH. Then pH, then calcium hardness, then stabilizer (CYA), and chlorine last. Make one adjustment at a time, let the pump circulate, and retest before the next one.
Can I lower CYA, calcium or salt with chemicals?
Not practically. Stabilizer, calcium and salt stay in the water until it is replaced. The calculator shows roughly what share of the water to drain and refill, assuming your fill water has none of that chemical.