About and methodology

Most pool chemical labels give a dose for 10,000 gallons and leave the rest to you. Most pool owners don't know their exact gallons. Small errors add up to cloudy water, a cell that shuts off, or a wasted bag of shock.

Poolside starts from your pool's volume and carries it into every other calculator, so each dose is for your pool, not a round number.

A gallon of water weighs 8.34 lb, and 1 ppm means one pound per million pounds of water. So the pounds of a pure chemical that raise a level by a number of ppm are:

gallons × ppm × 8.34 ÷ 1,000,000

Each calculator then adjusts for what the product really contains: its percentage of available chlorine, or the conversion for alkalinity and hardness, which are measured as calcium carbonate.

Every formula has automated tests against known reference values, for example 267 lb of salt to bring 10,000 gallons to 3,200 ppm, or 1.4 lb of baking soda to raise 10,000 gallons of alkalinity by 10 ppm. A change that breaks one of these can't be published.

• Pool volume calculator: how many gallons your pool holds.
• Pool salt calculator: how many bags of salt to add.
• Pool chemical calculator: chlorine, alkalinity, calcium, stabilizer.
• Pool shock calculator: how much shock to add.
• Pool pump calculator: flow rate, run time and cost.
• Pool heater calculator: btu size and heat-up cost.
• Pool fill cost calculator: water cost and time to fill.
• Pool chlorine calculator: how much chlorine to add.
• Pool heat pump size calculator: what size heat pump you need.
• Hot tub chemical calculator: spa chlorine, alkalinity and calcium.
• Hot tub electricity cost calculator: what your spa costs to run.

We don't replace a water test, the directions on a product label, or a pool professional who can see your pool. Pool chemicals are hazardous: never mix them, add them to water rather than water to them, and store them apart.