Calcium hardness calculator
PROCalcium chloride to raise calcium hardness.
Short answer: lb ≈ (gal/10k) × (ΔCH/10) × 1.25. 20,000 gal, +100 ppm CH = 25 lb calcium chloride. Enter your measurements above and the calcium hardness calculator returns the quantity, unit conversions and an estimated cost instantly, in imperial or metric — no sign-up needed.
What do you need to measure?
What is the answer?
Calcium chloride
25.00 lb
+100 ppm CH
How does the calcium hardness calculator work?
lb ≈ (gal/10k) × (ΔCH/10) × 1.25.
What does a worked example look like?
20,000 gal, +100 ppm CH = 25 lb calcium chloride.
What do people ask most?
›Target CH?
200–400 ppm for plaster pools; 150–250 for vinyl/fiberglass.
Which pool calculator should you use next?
Where can you learn more?
Read field notes on estimating and materials, or browse every calculator we make.