Pool Chemical Calculator & Spa

Pool Chemical Calculator & Spa tells you exactly how much chlorine, salt, baking soda, acid, calcium chloride and stabilizer to add to your swimming pool or hot tub. Enter your pool size and your water test results once, and get every dose in pounds, ounces, kilograms, grams, fluid ounces or litres, in the right order to add them.

POOL CHEMICAL CALCULATOR
• All doses from one water test: free chlorine, total alkalinity, calcium hardness, cyanuric acid (stabilizer) and salt
• Shows the order to add chemicals and what each product adds as a side effect
• Works in US gallons or litres

POOL SALT CALCULATOR
• How much salt to add to a saltwater pool to reach your chlorinator's target ppm
• Result in lb, kg and 40 lb, 50 lb, 20 kg or 25 kg bags
• How much water to replace when salt is too high

POOL CHLORINE CALCULATOR
• Liquid chlorine 10% or 12.5%, plain bleach 6% or 8.25%, cal-hypo 65% or 73%, dichlor and trichlor
• See how much stabilizer or calcium each chlorine product adds

POOL VOLUME CALCULATOR
• How many gallons or litres is my pool? Rectangle, round, oval and kidney shapes
• Shallow and deep end, feet or metres, above-ground pools and hot tubs

ALKALINITY, CALCIUM HARDNESS & STABILIZER
• Baking soda to raise alkalinity, muriatic acid or dry acid to lower it
• Calcium chloride to raise calcium hardness
• Cyanuric acid (conditioner) dose, or how much to drain when it is too high

WATER BALANCE (LSI)
• Langelier Saturation Index from pH, temperature, hardness, alkalinity, CYA and TDS
• Know whether your water will etch plaster or form scale

POOL HEATER SIZE & HEATING COST
• How long it takes to heat your pool or spa with a gas heater or heat pump
• Heater size in BTU/hr or kW for the time you want
• Compare heating cost: heat pump vs natural gas vs propane vs electric

POOL PUMP COST
• Running cost per day, month and year
• Single speed vs variable speed pump savings

HOT TUB CHEMICAL CALCULATOR
• Exact spa doses in grams and ounces for chlorine and alkalinity
• Recommended hot tub chlorine, bromine and pH levels

WHY POOL CHEMICAL CALCULATOR
• Every tool shows the formula, worked examples and its sources
• Recommended levels quoted from official guidance (CDC) and the Australian standard AS 3633, with links
• Calculations run on your phone; your numbers are never uploaded
• Light, fast and free

NOT A GOVERNMENT APP
Pool Chemical Calculator & Spa is an independent app. It is not affiliated with, endorsed by or acting for the CDC or any other government agency. Recommended levels are quoted from the official sources linked in the app.

Results are estimates. Always read and follow the directions on your chemical product labels, never mix pool chemicals, and keep them away from children.