What Are Sister Bra Sizes and How to Find the Perfect Fit
Sister bra sizes are the alternative sizes close to your own that can offer a better fit if your usual size feels off.
Since bra sizing can vary across brands, bra styles and and regions, knowing your sister sizes gives you more options to explore. This way, you can discover the best fit so you’re consistently comfortable and supported.
At AmpleBosom, our team of bra specialists are here to help you find the ideal fit, so you feel confident and comfortable every day. Call 01439 798388 if you would like to chat about sister sizes and get advice about bra sizes.
Sister Bra Size Chart: Find Your Alternate Sizes
Our sister bra size chart below provides an easy way to identify your sister sizes based on your current size. It offers eight alternative sister sizes to help you find a bra that fits perfectly.
Knowing your sister sizes gives you more options for finding bras that provide both comfort and support across different brands and styles. Once you’ve identified your sister sizes, you can explore various styles from AmpleBosom to find your ideal fit.
The example we’ve used here is for a 42F, but you can find a blank chart below and fill it in for your own size.
How to Read and Use a Sister Bra Size Chart
Understanding how to read a sister bra size chart can make all the difference in finding your best fit, so let’s get into it…
You have eight alternative sister sizes to choose from, depending on how the 42F bra fits.
If you’re going up in band size because your band is too tight, you will need to go down in cup size to keep the cup volume the same as your current bra. Equally, if you go down in band size, go up in cup size.
If your band size feels okay but the cup is not the right size, keep the band size the same and adjust your cup size. If the cup size feels too big, size down to a 42E. If the cup size feels too small, size up to a 42FF. This gives you 1” more or 1” less in the cup, respectively.
If the band is too tight and you want to increase the band size, you can try a 44E which gives you 2” more in the band and the same cup volume. You could also try 44F which gives you an additional 1” in the cup, or a 44FF for an additional 2” in the cup.
If the band size is too big, you could try a smaller band size. 40FF would have a 2” smaller back size and the same cup volume. Alternatively, you could also try 40F for 1” less in the cup, or 40E for 2” less in the cup.
Fill Out Your Personal Sister Bra Size Chart
Ready to find your sister sizes? Use our blank chart to figure out what your own sister sizes are. This personalised guide can help you narrow down sizes to try when shopping for bras.
Save this chart as a quick reference and explore AmpleBosom’s collection by size to find a bra that fits you flawlessly.
For help and advice with bra sizing and sister sizes, give our friendly team of experienced bra specialists a call on 01439 798388.
Sister Size Chart For 36 Bra Band Size: Find Your Perfect Match
Below is a sister size chart specifically for a 36 band size, showing how you can size up or size down depending on fit.
Click on each linked size to view the bras we have available in that size.
| Current Bra Size | Sister Size Down | Sister Size Up |
| 36AA | 34A | |
| 36A | 34B | 38AA |
| 36B | 34C | 38A |
| 36C | 34D | 38B |
| 36D | 34DD | 38C |
| 36DD | 34DDD/34E | 38D |
| 36DDD | 34F | 38DD |
| 36E | 34F | 38DD |
| 36F | 34FF | 38E |
| 36FF | 34G | 38F |
| 36G | 34GG | 38FF |
| 36GG | 34H | 38G |
| 36H | 34HH | 38GG |
| 36HH | 34I | 38H |
| 36I | 34J | 38HH |
| 36J | 34JJ | 38I |
| 36JJ | 34K | 38J |
| 36K | 34KK | 38JJ |
| 36KK | 34L | 38K |
| 36L | 34M | 38KK |
| 36M | 34N | 38L |
| 36N | 38M |
Using our charts you can locate your current bra size and see what your sister bra size is down or up a size.
Sister Size Charts for Each Band Size: Read Our Blogs
Each of the blogs below has a sister size chart tailored to the specified band size. Click on your current band size to discover your sister sizes.
Visit our bra page to view our comprehensive bra collection and you can filter by size to see the bras we have in your size and your sister sizes.
SALLY'S TOP FOUR EVERYDAY BRAS FOR COMFORT, FIT & SUPPORT
Here are four of Sally's Top Bra Picks....
Have you seen our popular Magic Lift Active Support Bra, a non wired everyday bra in cup sizes C to K, that's a favourite for comfort, fit and support.
Take a look at our best selling Cate Banded Bra, perfect for the fuller figure and giving amazing uplift, forward shape and good separation, in cup sizes DD to K, in a range of colours.
One of our best selling soft cup bras is the Doreen Classic Bra from Triumph offering it's famous comfort and support.
Another best seller here at AmpleBosom which customers love is the Keira Wired Bra, an everyday bra that is ultra supportive and comfortable in cup sizes DD to KK in classic and seasonal colours.
Understanding Band Sizes and Sister Sizes Across Brands
Bra sizing can vary by brand, which is why knowing your sister sizes is so important. We’ve put together a chart comparing cup sizes across some of the brands that we stock, so you can make an informed decision about which size is best for you.
Useful Links: Finding Your Perfect Bra
- Bra Measuring Guide - make sure you’re measuring your bra size accurately
- Bra Fitting Guide - expert tips on adjusting your bra for the perfect fit
- Bra Size Guide - compare bra sizes across brands and countries
- Which Breast Shape Am I? - advice on bra styles to suit different breast shapes
- Bra Style Guide - compare different bra styles
Arrange a bra fitting appointment here in North Yorkshire by calling us on 01439 798388.
Discover Your Perfect Fitting Bra at AmpleBosom
For expert advice on finding a comfortable, well-fitting bra, our friendly customer service team is just a phone call or email away. Call us on 01439 798388 or send us an email for personalised bra recommendations based on your unique measurements. We’re here to support you every step of the way.
Explore our extensive bra collection, featuring band sizes from 28 to 58 and cup sizes from AA to N, with styles to suit every body shape and lifestyle. You can easily filter by size to find bras in your size and sister sizes.
Join our Facebook group to connect with our team of specialists and like-minded ladies. It’s the perfect place to ask questions, seek advice, and find answers to common bra fitting questions. Stay in the loop with new arrivals, special offers, and trending styles, and share your favourite looks and brands with others.
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Written by AmpleBosom 09/01/2018 and edited by Sara 07/11/2024.