About Pool Calculator Hub

What is Pool Calculator Hub

Pool Calculator Hub is a free collection of pool chemistry and equipment calculators. Our calculators tell you exactly what to buy. Not raw numbers, real bags and bottles. Enter your pool dimensions and current chemical readings. We output the specific number of bags, ounces, or hours you need, plus product links to purchase exactly that amount.

This site has no named founder, no paid staff, and no sponsors. We earn a small commission on products purchased through our links.

Our Formula Sources

Every formula on this site traces to a named, published standard:

• CDC Model Aquatic Health Code, 2023 edition: FC (free chlorine) / CYA (cyanuric acid stabilizer) ratio requirements and health-based minimum chlorine levels for public aquatic facilities.
• ANSI pool-water standard (ANSI/PHTA/ICC-11): Primary standard for all chemistry target ranges and dosing formulas.
• DOE ENERGY STAR Pool Pumps v2.0: Used for pump efficiency ratings and variable-speed pump energy savings calculations.
• TroubleFreePool Wiki: Community-validated reference for CYA/FC minimum ratios per O'Brien et al. (1974).

We use the ANSI pool-water standard as the primary source for all chemistry target ranges. Full per-calculator formula derivations, external citations, and correction notes are documented on our Methodology page.

Per-Calculator Documentation

Each calculator formula, its sources, and any important correction notes are listed below.

Salt Calculator

lbs = (target PPM − current PPM) × volume × 8.34 ÷ 1,000,000Source: ANSI pool-water standard. Uses 7.48 gal/ft³ for volume conversion.

Chlorine Calculator

oz = fcChange × volume × 8.34 ÷ (product_pct × 1,000,000)Source: ANSI pool-water standard. CYA/FC minimum from O'Brien et al. (1974) via TFP.

Shock Calculator

lbs = fcChange × volume × 8.34 ÷ (0.65 × 1,000,000)Source: ANSI pool-water standard. Cal-hypo 65% purity.

pH Calculator

oz = delta_pH_units × volume × 0.83 ÷ 1,000 (muriatic acid, pH down)oz = delta_pH_units × volume × 2.0 ÷ 1,000 (soda ash, pH up)Source: ANSI pool-water standard. HOCl correction: at pH 8.0, approximately 25% of chlorine is active as HOCl. Some sources cite a much lower figure; this site uses the corrected value.

Alkalinity Calculator

lbs = (target − current) × volume × 8.34 ÷ (1,000,000 × 0.67)Source: ANSI pool-water standard. NaHCO₃ 67% purity factor.

CYA Calculator

oz = (target − current) × volume × 8.34 ÷ (0.35 × 1,000,000)Source: ANSI pool-water standard. CYA ≥80 ppm is a health risk per CDC recommendation.

Calcium Hardness Calculator

lbs = (target − current) × volume × 8.34 ÷ (1,000,000 × 0.77)Source: ANSI pool-water standard. CaCl₂ dihydrate 77% purity.

Pool Volume Calculator

Shape-specific formulas (rectangular, round, oval, kidney, L-shaped, freeform). All use 7.48 gallons/cubic foot for the ft³-to-gallon conversion. Source: ANSI pool-water standard.

Pump Run Time Calculator

daily_hrs = turnovers × (volume ÷ (gpm × 60))Source: DOE ENERGY STAR. Variable-speed pumps use approximately 75% less energy than single-speed pumps.

Affiliate Revenue

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