Pool Chlorine Dose
Calculator
Results
- Increase needed (ppm)
- 2.5
- Active chlorine needed (g)
- 125
- Product to add (g)
- 192.307692
- Product to add (kg)
- 0.192307
Pool and aquarium results
| Increase needed (ppm) | 2.5 |
| Active chlorine needed (g) | 125 |
| Product to add (g) | 192.307692 |
| Product to add (kg) | 0.192307 |
formula-map diagram
- Increase needed (ppm)
- 2.5
- Active chlorine needed (g)
- 125
- Product to add (g)
- 192.307692
- Product to add (kg)
- 0.192307
Pool and aquarium relationship
Formula
product = (target − current) × volume(m³) ÷ (strength ÷ 100)= 2.5
Note
This is a simplified model: it applies a standard geometric or physical formula to the numbers you entered. Volumes assume a regular shape and an even average depth, and the kidney shape uses the common 0.45 × (A + B) × L area approximation. Chemical doses convert a target change into a product mass using the strength or label dose you enter, because the amount of active ingredient varies from product to product; they ignore pH, temperature, buffering, sunlight, bather load and existing chemical interactions. Heating uses Q = m × c × ΔT with c = 4186 J/kg·K and ignores heat losses to air, ground and evaporation; evaporation and cover figures use the rate you enter, not local weather. Aquarium stocking by surface area is a rule of thumb, not a biological limit. Always follow the product label and test the water before and after dosing, and consult a pool or aquarium professional for anything you are unsure about.
More in Pool and aquarium
See all →Frequently asked questions
What target chlorine level does this calculator dose toward?+
It calculates how much chlorine to add to reach the recommended free-chlorine range of 1-3 ppm for residential pools, based on your current reading, pool volume, and the strength of the product you're using (liquid chlorine, granular dichlor, or trichlor). Free chlorine, not total chlorine, is the value that actually sanitizes the water.
Why does the same 'amount of chlorine' dose differently depending on the product I use?+
Different chlorine products have different available chlorine concentrations — liquid chlorine is typically 10-12%, granular dichlor around 56-62%, and cal-hypo around 65-73% — so the same weight or volume delivers very different ppm. The calculator adjusts the dose for the specific product's strength so you don't over- or under-shoot.
What's the difference between free chlorine and total chlorine?+
Free chlorine is the active, available sanitizer still able to kill bacteria and oxidize contaminants; total chlorine is free chlorine plus combined chlorine (chloramines) that has already reacted with contaminants and lost most of its sanitizing power. If total chlorine is much higher than free chlorine, that gap (combined chlorine) signals a need for shock treatment, not just routine dosing.
Why does the same dose raise chlorine less in a heavily used or sunny pool?+
Chlorine is consumed by UV light, bather load, and organic contaminants, so demand varies day to day even with identical starting readings. Cyanuric acid (stabilizer) also affects how fast chlorine degrades in sunlight — too little stabilizer means your dosed chlorine burns off within hours.
Should I add the full calculated dose all at once?+
For small corrections it's fine, but very large doses are best split across a few hours or added in the evening, since adding too much liquid chlorine at once, especially in bright sun, wastes product to rapid UV breakdown. Always run the pump while dosing to distribute chlorine evenly and avoid localized bleaching of vinyl or plaster.