Have you ever wondered how long it takes to boil water?

First of all, you need to understand that the word “boiling” in this aspect refers to the bringing of a quantity of water to the point or temperature at which it starts to transform from liquid to gas.

A lot can affect the time it takes for H2O to boil and this includes:

  • The temperature of the water, pot, and stove
  • The salinity of the H2O composition
  • Conductivity
  • Surface area
  • Altitude
  • The volume of the pot
  • Whether a lid is in place or not

There are, however, a few other factors that also affect the time or how long it takes for water to reach its boiling point.

Factors Affecting the Time It Takes To Boil Water


1. Atmospheric Pressure

Low air pressure, as well as thin air, makes water to boil more quickly at high altitudes.

This means that it takes a higher temperature to boil at low altitudes, i.e., at sea level. The boiling point – i.e., the temperature at which water starts boiling and turns from liquid to steam – begins to decrease as the elevation rises significantly.


2. Impurities

Impurities, as well as other substances that are soluble in water, can also affect the amount of time it takes for it to reach the boiling point. This is because some of the impurities will also be absorbing the heat or temperature that ought to have gone to the molecules of water.

Eventually, after they have had enough, at a slightly higher temperature than usual, the impurities start to boil along with the water.

Another example is salty water; it takes longer for it to boil because the salt that is present in the needs to vaporize first and it takes a tremendous amount of energy for that to take place.


3. Heat source

The heat source also plays a significant role. If, for instance, you attempt to boil say, 1 liter using a regular stove, it will take about 10-15 minutes for the water to reach boiling point. Even this outcome depends on the type of standard stove you are using.

If you make use of a water heater to boil 1 liter, it will take nothing less than 4-5 minutes to bring that quantity of water to a boil. This result also differs from one heater to another.

Microwave ovens are designed to be super fast, so it will take around 3-4 minutes to bring 1 liter of water to a boil. This depends primarily on the level power you set and whether or not the microwave oven is a standard one. More of this aspect will be discussed later on in this write-up.


4. Quantity of water

Without any doubt, it takes far longer to boil water in a large pot compared to a kettle or small pot. It takes a lot more energy because there is more aqua to bring to boil in a large pot than it will in a smaller one.


How Much Energy is Required?

The amount of energy that is required to raise the temperature of the water – i.e., 1 gram – by 1 Kelvin or degree Celsius is equal to 4,184 Joule, i.e., 1 calorie. So if, for instance, you want the temperature of say, 1 liter of water by 80 degrees Celsius, your calculation should look similar to the one below:

1 liter = 1,000 g for water.

The specific heat capacity of H2O is 4,184J/gram/Celsius. So, starting from room temperature of 21°C and taking it to 100°C which is the boiling point, the change in temperature is 79°C.

The energy required E = SH multiplied by the change in temperature multiplied by the total mass (in grams) is as follows:

4,184 x 79 x 1,000 = 330,536J or 330.54kJ.


Different Methods for Boiling H2O

In most cases, the technique employed for boiling water as well as the purpose of boiling it can also affect how long it will take for it to reach its boiling point.


1. For Purification

To get the best results, the first thing you should do is to filter the water to get rid of visible impurities before you boil it.

Then fill up the container with the water and place it on the lighted stove. When the water starts to boil with a lot of bubbles, leave it on the stove for a few more minutes so that all the harmful microbes or impurities will be eradicated from the water.

Continue boiling the water for the next 4-5 minutes. Then turn off the heat and allow the water to cool down. Keep it sealed so that it can maintain its cleanliness or purity.


2. Microwave Boiling

microwave oven

To boil water in a microwave oven, fill a microwave oven with water, but not to the brim. Then insert a microwave-safe object – such as a chopstick or a wooden spoon – in the bowl of water.

If you do not mind adding taste to the water in the microwave bowl, consider adding one spoon of sugar or salt.

They will help with the bubbles when the temperature of the water in the bowl reaches the boiling point.

Before you place the bowl in the microwave, please read the manual that came with the kitchen appliance to be sure you are not flouting any rules.

If you are not, then place the microwave bowl in the oven and switch on the heat. You can heat water in several ways with a microwave oven.

You can heat the water for about 1 minute, stir it with the chopstick or wooden spoon, and then heat it again, at one-minute intervals.

You will see that the water is boiled when it becomes hot and releases a lot of steam.


3. Boiling Water for the Preparation of Food

You will need a pot with a lid to enable the water to reach its boiling point more quickly. Don’t use a large container or pot as it will take an extended time for the water to boil.

Fill up the pot or container with tap water, but leave a few centimeters to the brim or top edge of the pot to give room for any food item you will eventually cook. Place the pot on a lighted stove and cover it with the lid.

Set the stove at low, medium or full heat though this depends significantly on what you intend to cook.

Next, add the food in the water on the stove, depending primarily on the recipe you are cooking. You can do this before or after the water in the pot has reached a boiling point. Then allow the pot and its content to simmer by applying medium or full heat.

What you need to bear in mind here is that cooking with or without a lid in place as well as the “impurities” – food item like rice, beans, etc. – affect the boiling of H2O.



There is no specific answer to the question “how long does it take to boil water?” This is because the amount of time it takes for water to reach the boiling point depends on several factors which include atmospheric height, the presence of impurities, etc.


Nick Davis

Technology blogs contributor, I love everything that's high-tech and super solid. While traveling, hiking and surfing, I make sure to put my gear to the toughest tests. Join me in my quest of discovering gadgets with superpowers!

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