How to Calculate Cubic Feet of a Microwave Easily at Home

One day, I was standing in the kitchen wondering if a new microwave would fit in my small corner shelf. The size looked fine, but something felt off. Then I noticed the specs said “1.2 cubic feet.” That made me think — how do you even find that number? It turns out it’s super easy once you know the trick. In this article, I’ll show you how to calculate cubic feet of a microwave in a simple way anyone can do.

To calculate the cubic feet of a microwave, you first measure the inside dimensions — width, height, and depth — in inches. Then you multiply them together to get cubic inches. Finally, divide the total by 1,728, because there are 1,728 cubic inches in a cubic foot. This helps you compare microwave sizes easily, whether you’re buying, replacing, or rearranging your kitchen space.

Measuring the Inside of Your Microwave Correctly

Before doing any math, you need to get the right measurements. Most people make the mistake of measuring the outside, but the cubic feet are based on the inside cooking space. So, grab a tape measure and open the microwave door. Measure the width from one inner wall to the other. Then measure the height from the floor of the microwave to the top. Finally, measure the depth from the back wall to the front edge, not including the door.

When I first tried this, I used a ruler, and the numbers were off. A tape measure is much easier because it bends into corners. Make sure to note all three numbers in inches. It’s okay if they are not even numbers like 13.5 or 17.2. Write them exactly as they are. Being precise will make your cubic feet result much more accurate.

Another helpful tip is to measure twice, just to be sure. Sometimes the microwave’s interior has curved corners, which can slightly change the size. It’s fine to round off to the nearest tenth if needed. Once you have these three numbers, you’re halfway done. You might be surprised how small or big your microwave actually is once you do the math.

• Always measure the inside, not outside.
• Use a tape measure, not a ruler.
• Write numbers in inches accurately.

Multiplying the Dimensions Together

Now that you have the width, height, and depth, it’s time to multiply them. This step gives you the total cubic inches. For example, if your microwave’s inside is 18 inches wide, 10 inches high, and 14 inches deep, you multiply 18 × 10 × 14. That equals 2,520 cubic inches. Pretty simple, right?

It’s funny how most people never realize the math behind those numbers on the microwave box. When you do it yourself, you’ll start to understand what 1.0 or 1.6 cubic feet really means in real space. You’ll see that a few inches can make a big difference when heating large plates or casserole dishes.

One common mistake is forgetting to multiply all three measurements. Some people only use two, thinking it’s like measuring a TV screen. But volume includes all three dimensions — width, height, and depth. Once you’ve done the multiplication, double-check your answer. Small errors can make your final number look strange.

• Multiply width × height × depth.
• Use all three measurements.
• Check your math twice for accuracy.

Converting Cubic Inches to Cubic Feet

After getting your total cubic inches, you need to convert it to cubic feet. This is where most people get confused, but it’s actually very simple. You just divide your total cubic inches by 1,728. That’s because there are exactly 1,728 cubic inches in one cubic foot. So, if your microwave is 2,520 cubic inches, you divide 2,520 ÷ 1,728. The result is about 1.46 cubic feet.

That number — 1.46 — is what you usually see on microwave boxes or websites. It tells you how much cooking space you have inside. You might think the difference between 1.2 and 1.6 isn’t much, but it really is when fitting large bowls or reheating leftovers.

It helps to use a calculator for this part to avoid mistakes. If you don’t have one handy, you can use your phone’s calculator app. Just remember to round the final answer to one or two decimals. This makes it easy to compare with standard microwave sizes you see in stores.

• Divide total cubic inches by 1,728.
• Round your answer to one or two decimals.
• Use a calculator for quick results.

Comparing Different Microwave Sizes

Once you know your microwave’s cubic feet, you can compare it to other models. Small microwaves usually range from 0.7 to 1.0 cubic feet, while mid-size ones go from 1.1 to 1.5. Larger family-size microwaves can reach 2.0 cubic feet or more. Understanding this helps when shopping or replacing your old one.

For example, I once replaced a 0.9 cubic foot microwave with a 1.3, thinking it would be just slightly bigger. But when it arrived, it took up almost all my counter space! So it’s smart to measure the space where your microwave sits before buying. Knowing your current size helps you pick one that fits both your kitchen and your cooking needs.

Also, consider how you use your microwave. If you mostly heat drinks or small snacks, a smaller size is fine. But if you often cook meals, reheat large plates, or pop big bags of popcorn, go for at least 1.3 cubic feet. The extra space makes a real difference.

• Small: 0.7–1.0 cu ft (snacks, drinks).
• Medium: 1.1–1.5 cu ft (daily use).
• Large: 1.6–2.0+ cu ft (family meals).

Checking Manufacturer Labels and Specs

Before you finish, it’s smart to check your microwave’s label. Most microwaves have a small sticker inside the door or on the back that shows the cubic feet. It might say “Oven Capacity: 1.1 cu ft.” This helps you confirm your math. Sometimes, manufacturers measure slightly differently, but it should be very close to your result.

When I did this for my old microwave, I was only off by 0.02 cubic feet. That showed me I had measured pretty well. It’s a nice way to double-check your calculation and feel confident that you understand what the numbers mean.

If the label has faded or is missing, don’t worry. Your own measurement is still accurate enough. The main goal is to know the real usable space inside your microwave. This also helps when buying dishes or containers that fit perfectly without touching the walls or spinning tray.

• Check the label for confirmation.
• Your math should be very close.
• Use it to choose the right dish size.

Understanding Why Cubic Feet Matter

Knowing your microwave’s cubic feet isn’t just about numbers. It helps you make smarter kitchen choices. For example, it saves you from buying a microwave too big for your space or too small for your plates. You’ll also understand why cooking times vary between models — more space means more air circulation and different heating patterns.

I once borrowed a friend’s 2.0 cubic foot microwave, and my popcorn cooked much faster than in my 1.0 one. That’s because the air and waves moved differently inside. Once you understand this, you can adjust cooking times more confidently and avoid burning food.

Also, knowing the cubic feet helps you plan your kitchen layout better. You can match your microwave’s size with your cooking habits, family size, and counter area. It’s all about making daily cooking smoother and easier.

• Bigger microwaves cook faster and hold more.
• Knowing size helps adjust cooking times.
• You can plan space and dishes more wisely.

Final Thoughts

Now you know how to calculate cubic feet of a microwave easily. It’s really just a few simple measurements and one quick division. Once you try it, you’ll start noticing how every inch matters when cooking or buying new appliances. Knowing your microwave size helps you make smarter, space-saving choices every day.

Frequently Asked Questions (FAQs)

Is it hard to calculate the cubic feet of a microwave?

Not at all. It’s actually one of the easiest kitchen measurements to do. You just need to measure the width, height, and depth inside the microwave in inches. Then multiply those three numbers and divide the result by 1,728. That’s it. Most people find it easier once they try it themselves. It’s simple math that helps you understand your microwave’s true size.

Can I measure the outside instead of the inside?

You can, but it won’t give you the real cooking capacity. The cubic feet measure only the space inside the microwave where food goes. The outside includes extra parts like the walls, control panel, and door thickness. So, always open the microwave and measure the inner space for accurate results. That’s the number that truly matters for cooking and fitting dishes.

Do I need special tools for measuring?

No, just a regular tape measure will do. You don’t need anything fancy or digital. A flexible tape measure is perfect because it can reach corners and curved edges easily. You can even use a phone calculator to finish the math part. Simple tools are enough to get an accurate number for your microwave’s cubic feet.

Is it okay if my numbers are a little off?

Yes, a small difference won’t matter much. If your math gives you 1.45 cubic feet and the label says 1.4, that’s perfectly fine. Rounding and curved corners cause tiny changes. What’s important is getting close enough to understand your microwave’s real size. Just make sure you measured the inside space correctly before rounding your answer.

Can I use this same method for ovens or fridges?

Yes, you can use the same process for any box-shaped appliance. The formula works for ovens, mini-fridges, or even storage boxes. Just measure the inside dimensions, multiply them, and divide by 1,728. It’s a handy trick to know when organizing your kitchen or checking how much space something offers.

Is it useful to know cubic feet before buying a new microwave?

Definitely. Knowing cubic feet helps you choose the right size for your kitchen and cooking style. For example, if you often cook for a family, aim for at least 1.3 cubic feet. But if you just reheat coffee or snacks, a smaller one works fine. Understanding this number saves you from buying something too small or too large.

Do I need to remove the turntable when measuring?

You can leave it in place. The turntable doesn’t affect the overall space measurement since it sits flat on the bottom. However, make sure to measure from wall to wall and top to bottom accurately. The turntable only helps with even cooking, not capacity. So you can keep it in while measuring without any issue.

Can I round my final answer to a whole number?

Yes, that’s fine. Most microwave specs round to one or two decimals. If your result is 1.46, you can say it’s about 1.5 cubic feet. Just don’t round too early during the math steps, or it might slightly affect accuracy. Save the rounding for the final result, and your number will still be very reliable.