Pool calculators
Everything about a pool starts with its gallons. Tell us yours once and every dose, heater and cost calculator here starts from it.
My pool
Total water in the pool, not the size of the shell.
Don't know your gallons? Calculate it
Shallow end plus deep end, divided by two. About 4.5 ft (1.4 m) for a typical backyard pool.
About 19,150 gal (72,491 L)
Your pool
15,000gal
56,781 L
Nothing is saved until you type a volume. It stays on this device and is never sent to us.
Pool volume & water
Every dose, heater and pump starts with gallons. Work out the volume of any pool shape, how long the hose takes to fill it, and how much water it loses in a week.
Pool Volume Calculator
Pick the shape, enter the size and depth, and get the water in your pool in gallons and litres, with a drawing of the pool to check it.
Pool Gallons Calculator
Pick your above-ground pool size and wall height, or enter an in-ground pool's dimensions, and see the gallons it holds.
Pool Fill Time Calculator
Enter your pool's gallons and how fast your hose runs, and see how many hours the fill takes and what the water costs.
Pool Evaporation Calculator
Enter your pool's surface area, pick your region and wind, and see the inches and gallons evaporation takes each week, with and without a cover.
Pool chemistry
Enter your test results and your gallons, and get the amount of each product to add, in the order to add it, in cups, ounces, pounds or bags.
Pool Chemical Calculator
Type in your test strip or kit readings and get a dosing plan in the right order, with the amount of each product and what to buy.
LSI Calculator
Enter pH, total alkalinity, calcium hardness and temperature, and see whether your water is corrosive, balanced or scaling, and what to change first.
Pool Calcium Hardness Calculator
Enter your pool size and calcium hardness reading, pick your surface, and get the pounds of calcium chloride to add or the share of water to replace.
Pool Salt Calculator
Enter your pool size, the salt you have and the level your system wants, and get the pounds and bags to add, or how much water to replace.
Pool Shock Calculator
Pick routine shock, SLAM or algae, enter your gallons, free chlorine and CYA, and get the amount of shock, what it does to calcium and CYA, and when to stop.
Pool Chlorine Calculator
Enter your gallons, free chlorine and CYA to get the chlorine target, the amount to add in gallons, ounces or litres, and the daily top-up.
Pool Stabilizer Calculator
Raise CYA with stabilizer or work out how much water to replace to bring it down, and see how the change moves your free chlorine and SLAM levels.
Pool Alkalinity Calculator
Enter your gallons and total alkalinity to get the baking soda or acid needed to reach your target, in parts small enough to retest between.
Pool pH Calculator
Enter pH now, your target, alkalinity and CYA to get the acid or soda ash dose, the alkalinity it will use, and how much TA changes the answer.
Muriatic Acid Pool Calculator
Choose your acid strength and whether you are lowering pH or alkalinity, and get the amount to pour, split into safe additions.
Hot Tub Chemical Calculator
Pick your spa size, chlorine or bromine, and your test readings to get small doses in teaspoons and ounces, with spa target ranges.
Heaters, pumps & filters
Size the heater for the temperature rise you want, the pump for your turnover rate, and the filter for the flow, then see what each costs to run.
Pool Heater Calculator
Enter your pool, the temperature you want and the hours you can wait to get heater size in Btu/h and kW, time to heat and cost for gas versus heat pump.
Pool Pump Calculator
Enter your pool volume, turnover goal and head to get the flow you need, the pump size and what a variable-speed pump saves each year.
Pool Turnover Calculator
Enter your gallons and pump flow to get turnover time and rate, or pick a target to get the GPM you need.
Pool Filter Size Calculator
Enter your pump flow or your pool and turnover goal to get the filter area you need and the sand to buy.
Pool costs
A low, typical and high price for the pool you are considering, the monthly payment on it, and what it costs to keep running.
Pool Cost Calculator
Pick the pool type, size and extras to get a low, typical and high price for your state, the monthly payment and what the first year of running it costs.
Pool Payment Calculator
Enter the pool price, your down payment, the interest rate and the term to see the monthly payment, the interest you will pay and how the balance falls each year.
Pool Resurfacing Cost Calculator
Enter the pool size and choose the finish to get a low, typical and high price for your state, with the drain, tile and coping lines you pick.