Pool Heating Time with Losses Calculator
Estimate heating time to a target water temperature with constant heater input and a linear heat-loss coefficient.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use an ideal mixed-water heat balance with constant supplied power and linearized total heat loss.
Cwater=ρVc; if UA>0, Teq=Tamb+P/UA and time=(Cwater/UA)ln((Teq−T0)/(Teq−Ttarget))
Worked example
10 m³ water at density 1000 kg/m³ and c=4186 J/(kg K) needs 418.6 MJ to rise 10 K before losses. A target at or above equilibrium cannot be reached in finite time.
Assumptions and input details
Target must exceed initial. Fixed approximate water density/heat capacity; UA is entered for the complete pool. Evaporation, radiation, wind, covers, stratification and heater cycling must be represented externally; no equipment sizing or guaranteed time.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
The 36 volume definitions distinguish US liquid, US dry and Imperial measures. Cups carry an explicit definition. Japanese shō is 2401/1331 L and a gō is one tenth of it; the explicitly labelled 180 mL rice cup is separate.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
NIST measurement tables · UK Imperial definitions · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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