Ice melts by absorbing heat, or energy. When we put an ice cube in the living room, it will begin to absorb the heat and melt. I wondered, how long will this take for an average sized ice cube?
How long does it take for an ice cube to melt? A 1 inch ice cube at 75°F room temperature (24°C) will take 45 to 60 minutes to melt. A standard 1 ounce cube (30 grams) will take 90 to 120 minutes to melt at the same temperature. The same 1oz (30g) ice cube submerged in a cup of hot water of 185° F (85° C) will take about 60-70 seconds to melt.
Keep in mind these are just averages and approximations, and how long will it take depends on many factors listed below.
Results may vary depending on a lot of factors, but with the calculation done and tested in practice, it’s very close to those times. The time it takes to melt the ice depends on how fast can you add heat, and how fast the ice cube absorbs the heat.
Main Factors that determine how fast the ice cube melts:
- temperature of the ice,
- air temperature of the room (or water if submerged in liquid)
- the mass, shape and volume of the ice
- the amount of volume of air in the room
- the insulation factors (rate of air transferring heat onto ice)
Let’s take a look at some of the interesting examples of how fast will the ice cube melt under different conditions.
How Long Does It Take for an Ice Cube to Melt in Cold Water?
A 1 inch ice cube, submerged in a cup of cold water would take about 15-20 minutes to melt. In a room temperature water, it would melt in 5-10 minutes.
I tried this myself, and it was 17 minutes. The time it takes for an ice cube to melt in cold water will depend on the ice temperature, ice volume, the temperature of the water and the water volume.
Melting an ice cube can be fun, try adding some salt or sugar in the water as well to see how that changes the time it takes.
Ice melts when heat energy causes the molecules to move faster. In this melting process, the water molecules absorb energy. The faster the absorption, the faster the ice cube melts.
How Long Does It Take for an Ice Cube to Melt in Boiling Water?
I tested this myself several times.
I put an ice cube in a typical cup of 8 ounces (240ml) filled with boiling water and it took 45 seconds for a 1 inch ice cube to melt.
The time it would take for an ice cube to melt in boiling water will largely depend from the temperature of the boiling water. If you tried this yourself now, we are bound to get the same results here.
How Many Ice Cubes is Needed to Cool Down Water?
To cool down 6.76oz (200ml) of water at 194°F (90°C) to 50°F (10°C) we would need 6 regular sized ice cubes of 1oz (30g).
To quickly cool down a cup of 16oz (470ml) of water (or tea) from 185°F (85°C) to 122°F (50°C) we need about 4 regular sized ice cubes of 1oz (30 grams).
This is the amount of ice cubes necessary to cool down water to a given temperature, meaning this amount is sufficient. Of course, if it’s a hot summer day, we will definitely put as much ice cubes as we can to cool our drinks. Why not?
Ice Cube Melting Experiment
There are many different experiments that you can do with melting ice cubes. Here’s a simple experiment you can do to answer the question: Which shape of ice cube will melt the slowest?
- Get a few different ice trays (cube, spherical and rectangle-shaped)
- Freeze them up with the same amount of water
- Take the cubes out and put them into 3 identical plastic cups
- Measure how much time it takes for the ice cubes to melt
Conclusion: Which ice cube melts the slowest? The larger the surface area of the ice cube, the more heat it will absorb, meaning the spherical shaped cube will melt the slowest.
Why? Because the less surface area the less heat can be absorbed by the ice and thus will melt less than the other types.
Which Ice Cube Will Melt the Fastest
If we take two very similar ice cubes, with same density and temperature, then the ice cube with largest surface area will melt the fastest.
Many good ice cube makers can make some nice looking ice cubes of various sizes and surface areas, like this one for whiskey and cocktail, or this one that makes crystal-clear ice cubes. Try one and test for yourself.
These cool factors determine when does one ice cube melt faster than the other:
- the temperature of the ice cube
Ice cubes can be chilled even below 32 degrees F, which is the temperature of the water freezing. The colder the ice, the slower it will melt. To have the ice melt faster, you would want close to 32F.
- Adding salt or sugar on ice cube will make it melt faster
Introducing foreign substances on ice, such as salt or chemical particles, will make ice cubes melt faster. The ice cube with salt melts faster because the air around it is warmer than 32°F.
When you add salt, it dissolves into the water of the ice cube. Salt water freezes at the lower temperature than the freshwater, and this is why salt is used to melt ice on sidewalks and roadways.
Here we can see how other substances affect the melting of ice, where the salt melts it the fastest out of these five.
However, there are other substances that can help with melting an ice cube, such as calcium chloride, magnesium chloride, or glycol, as shown in my blog post on the best ice melt. More on that in my next article on melting ice.
- putting ice cube in a larger cup of hot water will cause it to melt faster
If you were to try to melt ice in a cup of hot water, it would melt faster the bigger the cup is. This is because there is a larger volume of hot water to absorb energy from. If you were to put it a large block in a cup, it would cool down the water and be left with very little energy to absorb. As we know, cold water has less energy than warm water.
- putting a large block of ice in a large room will make it melt faster than if you put it in a smaller room (or a smaller container)
This is similar to the previous example: there will be a lot more hot air with energy that could be transferred onto ice, which in turn will cause it to melt faster.
There are many cool experiments which you can do with a cube of ice. Feel free to check the time of melting by yourself, and which factors affect it the most, but make sure to always stay safe while doing these experiments.
Non Melting Ice Cubes – what are they?
How do you keep a drink cool without watering it down with ice?
By using reusable ice cubes! Well, they’re not from “real” ice – they are cubes alright, but made out of different materials. Like these elegant gold Amerigo ice cubes.
You use them in your drinks, then once you’re done with them, you clean em up a bit, put them back in the freezer to use them the next time you need a cool drink. They look cool! And they last much longer than regular ice cubes.
They are usually made out of:
- stainless steel
- silica gel
The best sanitary solution are the steel and plastic ones, as silica gel filled ones can have a durability period that can expire. The soapstone ones are only good to maintain an already chilled drinks without dilution. Also, they can crack if used in a dishwasher due to high temperatures.
How Much Does an Ice Cube Weigh?
A typical ice cube, from a standard ice tray, weighs about 1 ounce, or 30 grams (28g more precisely, because of density of ice). A smaller 1 inch ice cube weighs about 0.53oz (15g).
How Long Does It Take for a Bag of Ice to Melt?
A 3lbs (1.5kg) bag of ice, at a room temperature of 73°F (23°C) will melt in approximately 5-7 hours. This will depend on many factors, such as outside temperature, the shape of the ice and, also whether the ice is inside or outside the bag.
How Long Does It Take a Gallon of Ice to Melt?
If the ice is inside a gallon container, in room temperature, it would take approximately 12-15h or longer. If it’s outside of the container, it would take about 6-8 hours, depending on a few factors.