Pool & Spa Calculators
6 calculators6 free calculators for pool & spa homeowners.
Algaecide Dosing Calculator
Calculate exactly how much algaecide to add to your pool. Enter your pool volume and algaecide type to get the precise dose for weekly prevention, season opening, or treating an active algae outbreak.
Chlorine Dosing Calculator
Calculate exactly how much chlorine to add to your pool. Enter your pool volume, current and target free chlorine levels, and chlorine product type to get the precise dose.
Pool Deck Resurfacing Cost Estimator
Estimate pool deck resurfacing costs by material — Kool Deck, concrete overlay, stamped concrete, or pavers. Enter your deck area and condition for an instant project cost range.
Pool Heating Cost Calculator
Calculate exact monthly pool heating costs for gas, electric, or heat pump systems. See seasonal expenses and compare heating methods.
Pool Salt Calculator
Calculate exactly how much salt to add to your pool. Enter your pool volume, current salt level, and target ppm to get the precise weight and number of 40-lb or 50-lb bags needed.
Pool Shock Treatment Calculator
Calculate exactly how much pool shock or bleach you need. Supports HTH, calcium hypochlorite, and liquid chlorine for any pool size (e.g. 12,000 gallons).
About Pool & Spa Calculators
Owning a pool or spa means making expensive decisions with incomplete information. You need to know exactly how much water your pool holds before you can buy chemicals, plan a drain, or understand your water bill. You need accurate calculations for pump sizing, filter capacity, and heating requirements—get these wrong and you'll either waste thousands on oversized equipment or watch your pool stay cloudy and cold.
This calculator hub gives you the math to make those calls confidently, converting your pool's dimensions into the gallonage and flow rates that actually matter for daily operation and maintenance. Beyond the basics, a pool or spa is a long-term investment that requires precise understanding of costs and timelines. You might wonder if it's cheaper to heat with a gas heater or heat pump, how long it really takes to fill your 20,000-gallon spa, or what size pump you actually need to turn over your water properly.
These aren't academic questions—they determine whether you spend $200 or $1,200 annually on heating, and whether you're maintaining a healthy pool or fighting algae blooms. Our calculators handle the conversions and formulas you don't want to get wrong, so you can make decisions based on actual numbers instead of guesses or salesman recommendations.