Swimming-pool calculators
Free, no-signup pool calculators for owners, DIYers and pool pros — volume and gallons by shape, salt and saltwater, water-chemistry dosing, heater sizing and running costs. Every tool shows its formula, a worked example and a reference table.
Pool Volume & Capacity
Gallons by shape — round, oval, rectangular, kidney — plus surface area.
All Pool Volume & Capacity tools →Saltwater & Salt
Salt to reach a target ppm, salinity changes and salt-system conversion.
All Saltwater & Salt tools →Water Chemistry
Chlorine, shock, pH, alkalinity, cyanuric acid and calcium — ppm dosing.
All Water Chemistry tools →Heating
Heater & heat-pump sizing, heat-up time, heating cost and solar sizing.
All Heating tools →Costs & Operations
Fill cost & time, pump energy, turnover, filter sizing and water loss.
All Costs & Operations tools →Pool Volume & Capacity
Saltwater & Salt
Water Chemistry
Heating
Costs & Operations
Built for practice — and to stay correct forever
SwimCalcs gathers the calculations pool owners and technicians reach for every week in one focused hub — in US units, without signup, with transparent formulas. Every tool shows not just the answer but the underlying formula, a worked example and a reference table.
Because the tools rest on geometry, water-chemistry math and stable constants (8.34 lb per US gallon, shape multipliers, ppm dosing factors, water specific heat), they stay correct with no maintenance — no water or energy tariffs, no product catalog, no live feeds. Cost tools use the rate you enter. More at Sources & formulas and About.