Boiling Water in Microwaves: Times for different cups and wattages

Always check the temperature of the water and container before touching it. Never microwave tightly sealed containers as this may result in a high-pressure, dangerous situation. Always use caution when heating anything with anything.

You need boiling water for a recipe and you only have a microwave or you just want to use a microwave.

We’ve tested this many times in a bunch of different microwaves. Both lower-powered ones and higher-powered ones.

How long does it take to boil 1 cup of water in a microwave? It typically takes 2 minutes at 100% power. If your microwave is smaller than average it will take 3 minutes and for larger, more expensive microwaves it will take only 2 minutes. For 3 cups of water, it will take 4 minutes.

In this post, you’ll find out not only how long it takes to boil 1 cup of water to a boil in YOUR microwave but many other volumes of water as well.

We even tested budget microwaves and some more expensive ones that have lots of power.

Can water be boiled in a microwave?

Yes, absolutely. We have done this many times and authoritative websites also extensively discuss microwaving water.

Some high-ranking websites say this is a bad idea, usually because the water cannot boil (LOL).

I’m here to tell you that yes, your water can and will boil, unless you have covered it and sealed it very tightly.

You should definitely NOT cover and seal the water you are microwaving. Doing so will result in very high pressures of very hot water being present in the container you are using.

If the container opens spontaneously (or in other words, explodes), you could get a faceful of incredibly hot water.

So be sure to not cover or seal the water you are microwaving tightly.

Does water need to be stirred after microwaving?

Microwaving water usually results in the top part of the water is much hotter than the bottom segment of water.

So if, for some strange reason, you plan to drink the water directly out of your coffee mug or glass, we do recommend stirring the water before you do so.

That is unless you just don’t care about the water being hotter at the top of your mug.

If you stir sugar or put much of anything else into the mug of hot water after heating it but before drinking it, the temperature differences should, for the most part, even out.

But always check the temperature of the water before you take a sip to prevent burns.

How long it takes to boil 1 cup of water

Most of you own typical microwaves: those with power ratings of 800-1000 watts.

In our tests, we found that boiling one cup of water with a typical 800-watt microwave takes 2 minutes and 40 seconds. If your microwave is high powered, like 1000-1200 watts, it will only take 2 minutes to bring water to a boil.

Boiling a full coffee mug (more than 1 cup)

If you are trying to boil water for tea or coffee, it’s important to keep in mind that your mug (like the one below) likely holds more than 1 cup (8 ozs / 250mls) of water.

It is more likely to be 1.25 “cups”, when filled nearly to the brim.

So one “mugful” or one “cupful” does not equal 1 cup (or 8 ozs / 235ml, the measurement unit) of water.

One cupful is actually 1.25 (measurement) cups.

So to determine how long it will take to boil one “cupful” or “mugful”, see our below table for the updated time.

You may not need boiling water

If you are trying to make tea or coffee, many recipes call for bringing water to a full boil before adding the coffee or tea.

But usually, coffee grounds or tea do not really need the water to steep or brew. So bringing your water to a near boil will also suffice.

Using water that isn’t quite boiling will also prevent bubbling water from burning your skin as you take it out of the microwave.

But water stops boiling almost immediately once the microwave turns off.

Don’t worry if your water is not bubbling when you take it out: as long as the water is very hot, it will still likely work for your application.

How long does to boil water in the microwave for tea?

If you are trying to microwave water for tea you do not necessarily need the full time that is listed in the tables above.

Tea will steep with water that is very hot but not quite boiling.

In our experience testing many microwaves for tea, setting your microwave’s timer for 1:30 suffices to get the water hot enough to make tea. We have tested this for green tea and black tea.

One benefit of not getting your water to a full boil for tea is that the water cools to the point of being drinkable a bit faster than if you fully boiled it.

This is because the peak temperature is lower than boiling, but still hot enough for brewing tea.

Is it bad to microwave water for tea?

No! It’s not bad to microwave water for tea. There are just pros and cons to heating your tea water in a microwave, electric kettle, or stovetop.

If you don’t have a kettle or stove to heat your water it is perfectly fine to use a microwave.

In fact, it is my preferred way of heating water for tea because the water is exactly the same temperature every time.

One benefit that we mentioned elsewhere in this post is that you can get your tea water very, very hot — hot enough to steep the tea — but not fully boiling. This results in your being able to actually drink your tea a bit sooner than if it fully boiled in an electric kettle.

Should I place the water in the center of my microwave?

No! Basically, the energy that heats things in your microwaves comes in actual waves. It is not an accident that microwaves are called… microwaves.

It is also not an accident that most microwaves have turntables. One of the purposes of spinning turntables in your microwave is to move your food around the inside of the microwave.

This ensures that your food doesn’t sit in one of the microwave’s cold spots and it cooks evenly.

These waves are 12cm long. And there are different patterns of the waves in each microwave depending on how it is constructed.

Actually many different factors affect where the hot spots are in your microwave but we don’t delve into that too much here..

Thus in your microwave, there are hot and cold spots.

This can easily be seen if you place a stationary, flat dish in the microwave that has the same thing spread over it. Shredded cheese would work great for this.

Once you microwave the cheese for a while you will see some of the cheese is melted and some aren’t! The part of the cheese that is melted was in the hot spots.

Obviously, the unmelted cheese was in cold spots.

We explore the science of microwaves elsewhere if you are interested in learning more about these fascinating devices.

How long to boil one mugful of water?

One “mugful” or “cupful” is more than 1 cup of water. It’s actually 1.25 cups, 10 ounces, or 300 MLS.

This table shows you how long to boil one mugful of water at various microwave power levels.

How long to boil water in a 700-watt microwave?

If your microwave is only 700 watts, don’t worry. You can still boil water in it. You will just have to wait a few seconds longer than if it was a more expensive, more powerful microwave.

In fact, having a smaller microwave like a 700-watt one is great if your countertop is small or you live in a small apartment.

How long to boil various volumes of water in a 700-watt microwave:

How long to boil water in an 800-watt microwave?

How long to boil various volumes of water in an 800-watt microwave:

How long to boil water in a 1,000-watt microwave?

How to boil various volumes of water in a 1,110-watt microwave:

How long to boil water in a 1,100-watt microwave?

Here is the table for times to boil various volumes of water in a 1,110-watt microwave:

How long to boil water in a 1,200-watt microwave?

Here is the table for times to boil various volumes of water in a 1,200-watt microwave: