Liquid chlorine 12.5%
61 fl oz
7.7 cups · 1.82 L
salt +3.3
You have the reading. Here are the ounces.
Type what the strip says. Get the ounces for the jug in your shed, at the strength on its label.
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Worked example
15,000 gal chlorine pool · CYA 40
Free chlorine — match your pad
0
0.5
1
3
5
10
20
Cal-hypo 73%
11 oz
312 g
hardness +2.5
Dichlor
14.4 oz
408 g
CYA +3.6 · TA −1.4
Same pool, same reading, three answers.
Works offline No account $5.99 once, no subscription Check the math yourself
Too big for one dose
Total alkalinity 60 → 90 ppm
6 lb 4.9 oz is more than one safe addition, so it splits and says when to retest.
Every dose calculation is free. Pro is $5.99 once — charts, LSI, reminders, full history.
Your App Store price applies.
Free vs Pro in full →Read before you add anything
If the product label and Pool Care Calculator disagree, follow the label.
- Never mix pool chemicals.
- Add chemicals to water, never water to chemicals.
- When in doubt: add less, circulate, retest.
Questions pool owners ask
Is there an app that tells me exactly how much chlorine to add to my pool?
Pool Care Calculator turns your test strip reading into an amount: enter the reading, your pool volume, the product you own and the strength on its label, and it gives the ounces to add, how to add it, a per-addition safety cap and how long to wait before you retest.
My pool's pH won't stay put. What should I fix first?
Pool Care Calculator puts the fixes in the order that works: sanitizer first, then alkalinity, then pH, then hardness, stabilizer and salt. Alkalinity goes before pH, with the amount on each line.
Does it work for hot tubs, bromine spas and salt water pools?
Yes. Volume comes from a shape template or a number you type, with no minimum, so a 350-gallon hot tub works. Target ranges change with the water, for example 4–6 ppm bromine for a spa on bromine, and stabilizer and salt targets for a salt pool.
Can a pool app read my test strip with the camera?
Pool Care Calculator deliberately has no camera. You hold the strip next to the phone and tap the matching on-screen swatch, or type the number if you use a drop test kit.
Why does the right chlorine level depend on stabilizer (CYA)?
Pool Care Calculator moves the chlorine target with your stabilizer instead of using one fixed number. At CYA 40 the floor is 3.0 ppm and the target is 5.0 ppm, so a reading of 1.0 is under the line.
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