Water Heating Time Calculator
Calculator that tells you how long it takes to heat water from start to end temperature with a given heating power.
The calculator supports Celsius/Centigrade, Fahrenheit, Watts (w), Kilowatts (Kw), Btuh, Joule, British thermal unit (Btu), liter, gallon, kg, lb, cubic inch, cubic foot etc.
The calculator supports decimal numbers, use dot or comma.
If you are using the calculator for swimming pool heating, please add a sufficiently large margin of safety to compensate for all the heat losses.
The formula to calculate the heating time of water is as follows:
(amount of water in kg) • (end temperature in °C – start temperature in °C) • (4168 joules/kg/°C)
(heating power in watts)
= heating time in seconds
To use the formula:
1) calculate the weight of water in kg
2) multiply that with the temperature difference in Celsius
3) multiply that with the constant of 4168
4) divide that by your heating power in watts
and the result is the heating time in seconds.
4168 is the constant for the heat capacity of water and means that it takes 4168 joules of energy to increase the temperature of 1 kilogram of water by 1 degree Celsius.
The heating power is in watts in the formula. A watt is defined as joules per second, e.g. 1W = 1 j/s = 1 joule per second.