Enter the mass of the ice and the power delivered to the ice per second to determine the total time to melt the ice.

Ice Melting Time Formula

The following formula is used to estimate the amount of time it takes to melt ice. 

T = HoF * m / P
  • Where T is the total time (seconds)
  • HoF is the heat of fusion of ice (335,000 J/kg)
  • m is the mass of the ice (kg)
  • P is the power delivered to the ice over time (Watts = Joules / Second)

In the case of this formula, it assumes the power or heat transferred per time is exactly constant. In real-world scenarios, this would not hold up as accurately.

How much time does it take to melt ice?

The amount of time it takes to melt ice depends on the size of the ice and the amount of heat being transferred to the ice per unit time.

The larger the ice cube, the longer it will take to melt.

The quicker the heat transfer, or greater the heat differential, the faster the ice will melt.

How to calculate ice melt time?

Example Problem:

The following example problem outlines the steps needed to calculate an ice cube melt time.

First, determine the heat of the fusion of ice. This is the amount of energy it takes for ice to change forms from ice to liquid per unit of mass. This is always a constant 335/kJ/kg = 335,000 J/kg.

Next, determine the mass of the ice cube. In this example, the mass of the ice cube is 3 kg.

Next, determine the power that will be transferred to the ice cube over time. In this case, the power transferred is 500 watts = 500 Joules/Second.

Finally, calculate the amount of time required to melt the ice cube using the formula above:

T = HoF * m / P

T = 335,000 * 3 / 500

T = 2010 seconds