Results are estimates
Rounded corners, steps, changing depth, pipework and the actual waterline can change the true volume.
Pool Explained
Pool calculations
Pool calculators: from dimensions to maintenance
Start with water volume, then estimate pump flow before calculating chemical adjustments. Check results against your equipment and product labels.
Choose a calculator
Which calculator should you use first?
The other calculations need water volume. Save that result and use consistent units so an error does not carry through to the next calculation.
Getting started
Pool volume
Estimate water volume from dimensions and average depth, ready for filtration, heating and dosing calculations.
Learn more CirculationRequired pump flow
Estimate flow from volume and target turnover time, then check it against the filter and pipework.
Learn more Adjusting water chemistryChemical dosage
Estimate a product quantity from water volume and the required change. Always check the product label.
Learn more Choosing heatingHeat pump size
Use volume, temperature rise and target warm-up time to estimate the required thermal output.
Learn more Heating timeHeating and heat loss
With a known heater output, estimate required energy, effective output and warm-up time.
Learn more BudgetRunning costs
Add pump electricity, top-up water, chemicals and consumables using your own prices and season length.
Learn moreCalculation order
From measuring the pool to checking the result
A calculator saves arithmetic, but a useful result still requires accurate inputs and a check of actual operating conditions.
- 1Measure internal dimensions and establish the actual average water depth.
- 2Keep the volume estimate: the same figure is used for pump, heating and chemical calculations.
- 3Calculate target flow, then check the pump curve, pipework resistance and filter flow limit.
- 4For chemicals, use the actual product label, enter values carefully and adjust gradually with retesting.
- 5For heating, estimate the energy first, then compare your target time, heater output and realistic losses.
- 6Finally, plan seasonal costs using your own tariffs, operating hours and consumable prices.
Limitations
What a simple calculation cannot cover
Check the result against your pool, equipment data and the specific chemical instructions.
Check flow against the installation
Pipework resistance, relevant elevation differences, the filter and connections determine actual pump flow.
Chemical strengths vary
The active ingredient, concentration and product instructions take priority over a general calculator estimate.
Retest between adjustments
Do not add several calculated doses in advance. Allow mixing as instructed, test again and then decide what is needed.
Using the results
More help with equipment selection and dosing
FAQ
Calculator questions answered
How accurate must my volume estimate be?
A good estimate often works for routine planning, but use internal dimensions and actual average water depth. Divide an irregular pool into simpler shapes.
Does the flow calculator select a pump model?
No. It provides a starting target. Choose the model using its pump curve, system resistance, filter, connections and manufacturer recommendations.
Does the dosing result replace the chemical label?
No. The specific product’s instructions and concentration take priority. Treat the result as a supporting estimate.
Why adjust chemicals gradually?
Volume estimates and tests have uncertainty. Gradual adjustment, circulation and retesting reduce the risk of overdosing.