Free calculators for homeowners and pool techs — work out your volume, dose chemicals, and balance your water. Instant results, shareable links, no email required.
Keeping a pool balanced comes down to numbers: how much water you have, how much of each chemical to add, and whether your water is in range. Free Pool Tools turns those numbers into quick, dependable calculators that work the same for homeowners and pool professionals — no sign-up, no app, no email.
Start with the pool volume calculator to find your gallons — it’s the foundation every chemical dose is based on. From there, our chemistry tools build on that volume to tell you exactly how much to add. Every result comes with the formula we used and a link you can share.
For everyday water chemistry, the chlorine, shock, and cyanuric acid calculators keep your sanitizer working, while the alkalinity, calcium hardness, muriatic acid, and water balance (LSI) tools keep the water from turning corrosive or scaling. Running a saltwater pool? The salt calculator sizes your salt dose, and on the equipment side the pump runtime, variable-speed pump savings, and heating cost calculators help you run the pool for less.
Every calculator uses standard, published pool-industry formulas, and each one shows the math behind its answer so you can check the work instead of trusting a black box. We treat dosing as health-adjacent: the numbers are careful estimates for planning, and you should always confirm your water with a reliable test kit before adding chemicals. You can read more about the formulas and sources we use on our methodology page. No sign-up, no app, no email — just open a tool and get your answer.
Yes — every calculator on Free Pool Tools is completely free, with no account, sign-up, or email required. Run as many calculations as you like.
Both homeowners looking after their own pool and working pool techs who need quick, reliable numbers in the field. The calculators handle in-ground and above-ground pools, plus spas and hot tubs.
Each calculator uses standard pool-industry formulas and shows the math so you can check it. Treat the results as solid estimates for planning and dosing, and always confirm your water chemistry with a test kit before adding chemicals.
Yes. Every tool builds a shareable link that restores your exact inputs, so you can send a result to a customer, family member, or friend and they will see the same numbers.
All of them are live. You can work out your pool volume, chlorine dose, shock dose, cyanuric acid (CYA), salt, muriatic acid, total alkalinity, calcium hardness, and water balance (LSI), plus run the numbers on pump runtime, variable-speed pump savings, and pool heating cost. Each one is a dedicated page with the formula shown and a shareable result.
For the chemical-dosing tools, yes — every dose scales with how much water you have, so an accurate volume is the foundation. If you do not know your gallons, start with the pool volume calculator (it handles rectangles, rounds, ovals, and varying-depth pools), then carry that number into the chlorine, salt, alkalinity, and other calculators.
Yes. The calculators are driven by water volume and your current readings, not the type of pool, so they work the same for in-ground and above-ground pools as well as spas and hot tubs. Just enter the right volume — small spas need much smaller chemical doses, and the math handles that automatically.