How to Actually Measure Your Bra Size at Home (Our Plus-Size Guide)

But what if you could take back control?

This guide is here to empower you. We’re going to walk you through a simple, no-fuss method to measure your bra size right in the comfort of your own home. This isn’t about finding one “magic” number, but about finding a reliable starting point for your journey to the perfect fit. So grab a measuring tape, and let’s do this together.

Before You Start: What You’ll Need

To get the most accurate measurement, gather these few things:

• A soft measuring tape: The kind used for sewing, not the metal one from a toolbox!
• Your best-fitting, non-padded bra: You should wear a bra that lifts and supports you into a natural shape, but without any extra padding that could alter the measurement.
• A mirror: So you can ensure the tape is straight.
• A place to jot down your numbers: A notebook or the notes app on your phone.

Step 1: Measure Your Band Size

This is the foundation of your bra’s support system.

1. Stand straight and wrap the measuring tape snugly around your ribcage, directly underneath your bust where your bra band would normally sit.
2. Make sure the tape is parallel to the floor all the way around (this is where the mirror comes in handy!). It should be snug, but you should still be able to fit a finger or two underneath it.
3. Breathe out to get the smallest possible measurement.
4. Read the number in inches and round it to the nearest whole number.

If the number you got is EVEN (e.g., 38), this is your band size. If the number you got is ODD (e.g., 41), you should try bras in both the size below and the size above (in this case, a 40 and a 42 band). Most women prefer to round up to the next even number. So, for 41, your starting band size would be 42.

Write down your band size.

Step 2: Measure Your Bust Size

This measurement determines your cup size.

1. Stand straight and wrap the measuring tape around the fullest part of your bust. This is usually at nipple level.
2. Keep the tape parallel to the floor. Make sure it’s not too tight—you don’t want to squash or compress your breast tissue. It should just skim your body.
3. Read the number in inches and round it to the nearest whole number.

Write down your bust measurement.

Step 3: Calculate Your Cup Size (The Simple Math)

Ready for some basic subtraction? This is how you find your cup letter.

Your Bust Measurement – Your Band Measurement = Your Cup Size

Example: Your bust measurement is 49″ and your band size is 42″. 49 – 42 = 7 inches

Now, use the chart below to convert that number into a cup letter. Every inch of difference equals one cup size.

In our example, a 7-inch difference equals a US G cup or a UK F cup. So, the starting bra size is 42G (US) / 42F (UK).

Plus-Size Pro Tip: Pay attention to UK vs. US sizing! Many of the best plus-size brands (like Elomi and Panache) use UK sizing, which is different after a DD cup. Always check which system a brand uses.

You Have Your Size… Now What? The Fit Check

Remember, the measuring tape only gives you a starting point. Your body is unique, and the final test is always trying on the bra. A bra that fits perfectly should check all these boxes:

• The Band: Should be snug and parallel to the floor. You should only be able to fit two fingers underneath. It provides 90% of the support!
• The Center Gore (Front Panel): The piece between the cups should lie flat against your chest without gaping.
• The Cups: Your breast tissue should be fully contained within the cups without any spilling over the top (“quad-boob”) or gaping.
• The Straps: They should sit comfortably on your shoulders without digging in. They are only there for about 10% of the support, not to do all the heavy lifting!

Your Journey to the Perfect Bra Starts Now

Congratulations! You now have a reliable starting size and the knowledge to check for a perfect fit. A great measurement is a powerful tool, but it’s useless without a well-constructed, high-quality bra to match.

Ready to put your new size to the test?

We’ve already done the hard work of finding the best bras on the market that are specifically designed for support and shape.

Read Our In-Depth Guide: [The 7 Best Supportive Bras for Large Busts in 2025] 

Finding the right bra can be life-changing. It can improve your posture, make your clothes fit better, and boost your confidence. You deserve to feel amazing every single day. Happy bra hunting!