Can You Boil Water in Microwave? (Solved)

Categorized as Microwave Safety
can you boil water in microwave

Do you need some boiling water for your beverage or food but don’t want to wait for a pot to boil on the stove? You may have noticed that some instant foods include instructions to nuke water in the microwave before adding the product. But is it really okay to use your microwave to boil water? Is this an approved method of bringing water to a boil, or does it come with health risks?

Can You Boil Water in the Microwave?

You can boil water in the microwave. Using a microwave to boil water is much quicker compared to using the traditional stovetop. You can have a cup of boiled water for your coffee and tea in as short as a minute!

Another benefit of boiling water in the microwave is that they are energy-efficient. While this will not significantly reduce your electricity bill, it does use less energy than boiling water the traditional way, such as on the stovetop.

Last but not least, boiling water in the microwave is a quick and proven way to sterilize water. Three minutes in a 700 wats microwave is more than enough to kill water-borne parasites and microorganisms.

Here’s a short guide on how to boil water in the microwave:

Get a microwave-safe cup or bowl and pour the desired volume of water. Microwave for one and a half minutes and check to see if the water is boiling. If it isn’t, microwave for an additional one and a half minutes, give a stir every 30 seconds.

For more details, see my step-by-step guide below.

How Long Does It Take to Boil Water in the Microwave?

On average, it takes one to three minutes to boil a cup of water in a 700-watt microwave.

When it comes to microwaves, wattage is directly proportional to the time required to bring a cup of water to a boil. The higher the microwave wattage, the faster it will reach boiling point.

Here’s a table detailing the estimated time it takes to boil water in different wattages:

Microwave WattsEstimated Time
600 watts4 minutes
700 watts3 minutes
800 watts2.5 minutes
1,000 watts2 minutes
1,200 watts1 minute

What Factors Determine How Long It Takes To Boil Water in the Microwave?

While wattage is important in determining how long it takes to boil water in the microwave, there are other factors that may lengthen or shorten the boiling time. Here’s a complete list of different factors that determine how to bring water to a boil in the microwave:

  • The power of the microwave: Microwaves with higher wattage take less time to bring water to a boil (see table above)
  • The volume of the water. More water equals a longer time required for it to come to a boil.
  • The material of the container is used to boil water in the microwave. Ceramic cups heat water faster compared to glass or plastic cups.
  • The starting temperature of the water. Water with a lower temperature takes more time to come to a boil than water at room temperature.
  • The efficiency of your microwave. Older microwaves may take longer to bring water to a boil compared to newer microwaves since their magnetron tubes may have worn out over time.

How to Boil Water in the Microwave

The microwave method is best used for boiling a small amount of water for a single cup of coffee or tea. However, if you plan on boiling more than that, it’s best to stick with the traditional stovetop method.

  1. Measure how much water you will need and pour it into a microwave-safe cup.
  2. Get a wooden spoon or other non-metallic object and place it in the cup.
  3. Place the cup in the microwave, set the power level to high, and time it for one and a half minutes.
  4. Gently tap the side of the cup to check if the water is already boiling.
  5. Remove the container from the microwave

1. Pour the Water in a Microwave-Safe Cup or Bowl

The first step in boiling water in the microwave is to pour the desired volume of water into a microwave-safe cup or bowl. Glass or ceramic cups are the best options. Don’t use plastic containers unless it’s rated for microwave use.

Another thing to note is that you should not seal or cover the container when microwaving water. This is because the sudden build-up of hot steam may cause the container to explode.

2. Get a Non-Metalic Stick or Object and Place It in the Cup

From a safety point of view, this is the most important step in the process. By placing non-metallic objects such as a wooden spoon, a chopstick, or a popsicle stick in the cup of water while microwaving, you’ll prevent a dangerous problem called superheating.

If you don’t have such materials on hand, you use a container that has a scratch inside the interior surface; even a spoonful of salt or sugar will do the job as long as you don’t mind the resulting flavor.

3. Put the Cup in the Microwave and Heat in Short Intervals

The next step is to place the cup of water in the microwave. Then, turn on the microwave at maximum power and heat in short intervals of no more than one and a half minutes each.

After each short interval, stop and give the water a good stir. Repeat this process until you see that the water is boiling.

Stirring is another way to prevent superheating since it ensures that the hot and cold spots in the cup are evened out, so all parts of the water get to boil at around the same time.

4. Tap the Side of the Cup To Check If the Water Is Already Boiling

After two to three intervals of heating the water, carefully take out the cup or bowl and tap its side. This action will disturb the water inside the cup and cause the water molecules to release some of the trapped heat. When you see bubbles forming, the water is already boiling.

Remember once again that the water will still reach boiling temperature even if you don’t clearly see any visible bubbles.

For a better way of knowing if the water is already boiling, you can also use a food thermometer. At sea or ground level, water boils at around 212 degrees Fahrenheit. But if you’re in an area where the elevation is higher, water boils at a lower temperature due to the lower air pressure.

If the water does not seem to be boiling, place the cup back in the microwave and increase the length of each interval from one and a half minutes to two minutes.

5. Carefully Remove the Container From the Microwave

The last step is to carefully remove the container from the microwave. Use kitchen mitten or hot pads to protect yourself from burns.

Is It Safe To Boil Water in the Microwave?

For years there has been an ongoing debate whether you can actually boil water in the microwave. Many people say that it’s not safe, while proponents claim that they can do it safely all the time.

Based on what I’ve learned so far, no conclusive evidence suggests that microwaves can cause cancer. Therefore, it is safe to boil water in the microwave as long as you follow the safety tips I’ve mentioned in this article.

Risks of Boiling Water in the Microwave

That said, there are still some risks to microwaving water.


The biggest risk is superheating, or when the water does not appear to be boiling but is, in fact, boiling. When this happens, hot steam builds up inside the cup and can cause it to explode when you remove it from the microwave oven.

Superheating happens due to the way microwaves work. They heat water molecules at random spots. If the water molecules are not agitated enough by stirring, some areas in the cup can reach much higher temperatures than the rest. As a result, a pocket of boiling water will start to develop below the surface, and there will be no bubbles on the surface to tip you off.

This is dangerous because the water can explode when you take out the boiled water from the microwave.


Another risk is burning. Be extra cautious when removing a microwaved cup of water from the microwave. To protect your skin, be sure to use pads or mittens when removing them from the microwave.

You should also only boil water in the microwave in a microwave-safe container.

If you do accidentally get burned, run cold water over the area to reduce any swelling or pain. You can apply aloe vera or burn cream after that to speed up your recovery.

Safety Tips To Prevent Superheating

Here are some tips to keep yourself safe when boiling water in the microwave:

1. Don’t Heat the Water for Long Periods of Time

Perhaps the single biggest thing you can do to avoid a superheating accident is to not heat the water for long periods of time. To be safe, try to nuke the water in short intervals. Start at a one-minute segment at first, then adjust the duration from there.

2. Avoid Using a Container With Extremely Smooth Surface

Don’t use a brand new, perfectly smooth container that you just bought from the store. Instead, it is best to use a container that has starches in it so that the water can form tiny bubbles.

3. Place a Non-Metalic Object in the Container

For the same reason, place a non-metallic object in the container. I use a wooden spoon, but you can use also use a chopstick or popsicle stick.

4. Carefully Tap the Side of the Container To Check the Water

Once you have microwaved the water long enough (at least 3 minutes), take a long tool and gently tap the side of the cup. If the water is superheated, you’ll see a sudden burst coming out of the container.

The water may be spilled out of the cup into the microwave, but you won’t be burned since you haven’t removed it yet. This is your signal that you should stop microwaving it and let the water rest before taking it out of the cup.

5. Frequently Stir the Water

During microwaving, you should periodically stir the water to give it nucleation sites for bubbles to form. If the water is superheated, you will see a rapid burst of steam coming up.

6. Keep Your Face Away From the Container

Make sure to keep your face away from the cup to avoid injury if it does explode. Most injuries when microwaving water result from superheated water bursting out of the cup and hitting the face.


In conclusion, you can boil water in a microwave oven. You don’t have to worry about health risks since, so far, there is no evidence suggesting a link between microwaved water and cancers.

However, there are risks involved if you don’t follow the right steps for boiling water in a microwave oven. The two biggest risks are superheated and burns. Be sure to follow all the safety tips that I have laid out here to protect yourself.

By Rosie Elliott

I’m Rosie. I’m a professional chef with experience in Western, Mediterranean, and Italian cuisine. I’ve been cooking for over 15 years, and I have two daughters that keep me busy!