Choosing the Right Implant Size for MTF Top Surgery

The right implant size for MTF top surgery is the largest volume that suits the width of your chest and that your skin and muscle can cover comfortably, matched to the shape you want. For most trans women that means a wider, often larger implant than a cisgender woman of the same height would have, placed under the chest muscle. Your surgeon measures your chest, assesses your skin and any existing breast tissue, and lets you try sizers before you decide.

There is no single “best” MTF breast augmentation size, and choosing one is a shared decision. This guide explains why a masculine chest needs a different approach, which measurements matter, how cc relates to cup size, which profiles suit a wider chest and what happens if an implant is too big. It also covers fat transfer and hybrid options, asymmetry, realistic expectations and changing size later. Our MTF top surgery page covers the procedure as a whole, and hormone therapy is not required beforehand, as our guide to MTF breast augmentation without hormones explains.

What Size Implants Do Trans Women Usually Get?

In published studies, most trans women have implants of about 300 to 600 cc, with averages of roughly 350 to 500 cc. Those figures describe what other people chose, not what you should have, but they show how MTF breast augmentation sizes differ from cosmetic augmentation.

A 2023 retrospective cohort study in the Annals of Plastic Surgery ↗ compared 153 trans women with 250 cisgender women having a first breast augmentation at the same centre. The trans women had a wider breast base, and their median implant size was 500 mL against 350 mL in the cisgender group^[1]. In Amsterdam, the median implant size for trans women rose from around 250 to 275 cc in earlier decades to 375 cc between 2010 and 2019^[2], and a Swiss series reported an average of about 363 cc in its most recent period^[3]. Sizes have crept up as surgeons have recognised that a broad chest needs more volume to look proportionate.

Why Is MTF Breast Augmentation Sizing Different?

MTF top surgery follows the same principles as cosmetic breast augmentation, but a chest shaped by testosterone during puberty differs in ways that change implant size, shape and position:

• A wider chest. A narrow implant on a broad chest looks small and leaves a wide central gap, so implants are usually wider.
• Tighter skin. Chest skin that has never stretched over breast tissue limits how much volume can go in at one operation.
• Stronger pectoral muscles. A thicker muscle covers the top of the implant well but presses on it and can push it upwards or outwards when it contracts.
• Nipples set wider apart. Nipples sit further from the midline, with a short distance to the fold below, and the implant needs to sit centred behind each nipple.
• Less breast tissue. Even on hormones, breast development is often modest, leaving less natural tissue to soften the implant edges.

In a detailed planning study from Johns Hopkins, trans women had a median breast base width of 15 cm and a nipple-to-midline distance of 12 cm, and the surgeons recommended routinely lowering the breast fold so that the implant sits correctly behind the nipple^[4].

Hormones help, but rarely enough on their own. A 2018 prospective multicentre study in the Journal of Clinical Endocrinology and Metabolism ↗ of 229 trans women found that after a year of hormone therapy almost half (48.7%) measured less than an AAA cup, with most growth in the first six months^[5]. If you take oestrogen, it usually makes sense to plan your size once growth has levelled off; our MTF breast growth timeline explains when that usually happens.

How Is Implant Size Measured for MTF Top Surgery?

Your surgeon starts with measurements rather than a target cup size. The four that matter most are:

• Base width: the width of the area where each breast will sit. It sets the diameter of the implant, which is the single most important choice. Too narrow leaves gaps; too wide sits out under the arm.
• Nipple-to-fold distance: measured with the skin gently stretched. On a masculine chest it is short, so the new fold is often set lower, and the incision of around 5 cm is hidden in it.
• Soft-tissue pinch thickness: how thick the skin and fat are above and below the nipple. Thin cover makes edges and rippling easier to see.
• Skin stretch: how far the lower chest skin stretches forwards. Tight skin limits safe volume; looser skin needs enough volume to fill it.

Your surgeon will also note the distance from the top of the breastbone to each nipple, the shape of your ribcage and any difference between the sides. Together these give a range of implant widths and volumes that suit your frame, and you choose within that range.

How Many cc Is a Cup Size?

Implants are measured in cubic centimetres (cc), not cup sizes. As a rough guide, 150 to 200 cc adds about one cup size, but cup size varies between bra brands and depends on band size. Trans women often have a larger band measurement, so the same volume spread across a wider chest gives a smaller cup letter. A 400 cc implant might give one person a full C cup and another a modest B cup.

Volume also adds weight. Silicone gel weighs roughly a gram per cc, so a 500 cc implant adds about half a kilogram to each side, which affects how much the skin stretches over time. Our guide to breast implant sizes explains the cc-to-cup relationship in more detail.

Which Implant Profile Is Best for MTF Top Surgery?

Implants come in low, moderate, high and extra-high profiles. For a given width, a higher profile holds more volume and projects further forward. On a broad chest, the implant width is usually matched to your base width first, and the profile then decides volume and projection:

• Low and moderate profiles are wide and soft-looking and fill a broad chest well. The Swiss study used round, low-projection implants in most patients^[3].
• High and extra-high profiles give more fullness from a narrower base. They can suit a narrower chest or a fuller look, but they put more pressure on thin tissue.

Round implants are standard for most MTF top surgery, as they look the same whichever way they turn; teardrop implants are used selectively. Centre for Surgery uses Silimed silicone implants in a wide range of widths, profiles and volumes. Our breast implant options page compares fill, shape, surface and profile.

Can I Try Implant Sizers Before MTF Top Surgery?

Yes, and it is one of the most useful parts of the consultation. Sizers are sample implants placed inside a fitted, non-padded bra so you can see how different volumes look under clothing and in a mirror. Your surgeon will usually offer sizers within the range that suits your measurements, so you are comparing sensible options.

• Wear a close-fitting top like the clothes you wear most days.
• Bring photos of results you like, ideally of people with a similar frame and shoulder width.
• Try the “rice test” at home, wearing a bag of rice of the volume being discussed in a bra for a day.
• Allow for the muscle. An implant under muscle and skin looks a little smaller and flatter than the same sizer in a bra.

Size is confirmed again at your pre-operative appointment, so you have time to reflect after your first consultation.

How Big Can MTF Breasts Get?

How big MTF breasts can get is limited by your skin, your chest width and the tissue covering the implant, not by the implants available. An implant too large for the space stretches the skin and muscle, tends to look less natural and ages less well. Where your goals are larger than your skin will safely allow at one operation, your surgeon may discuss:

• A staged approach: a moderate size first, with a larger implant later once the skin has stretched.
• Tissue expanders, only where clinically indicated, such as very tight skin. The expander is filled gradually over several weeks, and the final implant goes in three to six months later.
• Fat transfer on top of an implant, adding volume and softness without stretching the pocket in the same way.

It pays to be honest about the size you want. In a 20-year study of 138 trans women in the Aesthetic Surgery Journal ↗, a request for larger implants was the most common reason for revision, and those patients chose implants on average about 107 cc larger second time round^[3]. In Amsterdam, 2.5% of patients went on to request larger implants^[2].

What Happens If Breast Implants Are Too Big?

An implant too large for your chest width, or for the skin and muscle covering it, puts constant pressure on the surrounding tissue. The main problems are:

• Rippling and visible edges where cover is thin, especially at the sides and cleavage. See our guide to breast implant rippling.
• A stretched lower pole, where the weight of the implant stretches the skin below the nipple so the nipple sits too high.
• Bottoming out, where the implant slips below the breast fold. A lowered fold on a masculine chest can be more vulnerable if the implant is too heavy.
• Nerve stretch, which can increase nipple numbness or over-sensitivity, as explained in our article on nipple sensitivity after MTF top surgery.
• Capsular contracture, tightening of the scar tissue around the implant. It was the most common complication and reason for reoperation in both trans and cisgender women in the 2023 study^[1].

In cosmetic augmentation, US regulatory trials reported reoperation rates of 14% to 24% at three years, and planning implant size around the patient’s own tissues, rather than a target cup size, is one of the steps recommended to reduce them^[6]. In trans women the evidence is reassuring: a Swedish study of 143 patients found no difference in complications between implants under 400 mL and those of 400 mL or more^[7]. A large implant is not a problem in itself on a broad chest; the risks come from an implant that is too big for your frame.

Why Are MTF Implants Placed Under the Muscle?

At Centre for Surgery, implants for MTF top surgery are usually placed under the pectoral muscle, through an incision of around 5 cm in the fold beneath the breast. The muscle adds cover over the upper half of the implant, where natural breast tissue is thinnest, which softens the slope from the upper chest, hides the upper edge and lowers the risk of visible rippling.

The muscle also compresses the implant slightly, so the same volume looks a little flatter than it would above the muscle. Placement above the muscle is occasionally suitable where hormone therapy has produced more breast tissue. The fold scar heals as a fine line in the crease, and our guide to minimising scars after MTF breast augmentation explains how to care for it.

Can Fat Transfer or Hybrid Augmentation Give a Softer Look?

Yes. Both are options when you want a softer feel or when implant edges are likely to show.

• Fat transfer alone uses your own fat, taken by liposuction from areas such as the abdomen, flanks or thighs and injected into the chest in fine layers. Typically 60% to 80% survives and is then permanent. It gives a modest increase, and a second session can be done 6 to 12 months later.
• Hybrid augmentation combines an implant for volume with a layer of fat over and around it. The fat thickens thin cover, softens the upper edge and can partly narrow a wide gap between the breasts. Our page on hybrid breast augmentation explains how it works.

A hybrid approach can sometimes allow a slightly smaller implant for the same overall size, but it adds a liposuction site and some extra recovery.

What If My Chest Is Asymmetrical?

Almost everyone has some difference between the two sides. The ribcage may be more prominent on one side, the nipples may sit at different heights, or there may be a dip in the breastbone (pectus excavatum). Hormone-driven breast growth is also often uneven.

Your surgeon will point out any asymmetry at consultation and record it in your photographs. Implants can be different sizes or profiles on each side, and fat transfer can even out contour, but implants cannot fully correct differences in the ribcage or nipple position, so some asymmetry usually remains. Reoperation for asymmetry is uncommon, at around 3.6% in the studies reviewed by the Amsterdam team^[2].

What Results Can I Realistically Expect?

Good planning gives a breast shape that suits your frame and looks natural in clothes, but it cannot change the structure of your chest.

• The gap between the breasts may stay wider than in many cisgender women. Implants under the muscle cannot sit much closer together than the muscle’s attachment to the breastbone allows, so cleavage usually comes from a bra rather than at rest.
• The breasts look high and firm at first and settle over the following months, with the final result at around three months.
• Bigger does not mean happier. A small 2026 BREAST-Q survey of 65 trans women at least a year after augmentation found that satisfaction was not linked with implant size, shape, texture or incision; factors such as smoking mattered more^[8].

Before-and-after photos are most useful when the person had a similar starting chest, height and shoulder width to yours. Your surgeon takes clinical photographs at consultation and follow-up so you can compare your result with your starting point. You wear a surgical bra for six weeks and sleep on your back for at least eight weeks, as set out in our MTF top surgery recovery guide.

Can I Change My Implant Size Later?

Yes. Implants can be exchanged for a larger or smaller size in a later operation, usually through the same fold incision. Wait until your result has fully settled, as breasts that look too small or too large in the first weeks often look different by three months, and your surgeon will advise on timing. In the Swiss study, exchanges for larger implants took place typically around six months after the first operation^[3].

Going larger is usually straightforward once the skin has stretched. Going smaller can be harder, as stretched skin may not shrink back and a breast lift is sometimes needed. Our breast implant replacement and revision page explains what is involved.

Keep your implant card, which records the make, model and size of your implants. Centre for Surgery submits details to the national Breast and Cosmetic Implant Registry, so you can be traced if a safety concern ever arises with a particular implant.

Frequently Asked Questions

MTF Top Surgery in London

MTF top surgery at Centre for Surgery is performed by GMC-registered surgeons at our CQC-regulated Baker Street hospital, rated Good overall by the CQC, for trans women and transfeminine people aged 18 and over. We use Silimed silicone implants, usually placed under the muscle through an incision of around 5 cm in the breast fold, with saline implants or tissue expanders only where clinically indicated; fat transfer and hybrid options are also available. Your implants come with a ten-year warranty covering grade III and IV capsular contracture and implant rupture, and we submit details to the national breast implant registry. Hormone therapy is not required, and no diagnosis or referral letter is needed. The consultant who assesses you is the consultant who performs your surgery, and we recommend a two-week cooling-off period before you go ahead. Your initial consultation fee is redeemable against the cost of surgery if you go ahead. Finance is available, subject to status; see our finance options.

Phone: 020 7993 4849 | Address: 95–97 Baker Street, Marylebone, London W1U 6RN
Contact us to schedule a consultation

References

1. Torres Perez-Iglesias CA, Heyman A, Koh DJ, et al. Technical and clinical differences between transgender and cisgender females undergoing breast augmentation. Annals of Plastic Surgery 2023;91(5):534–539. doi:10.1097/SAP.0000000000003706 ↗
2. Sijben I, Timmermans FW, Lapid O, et al. Long-term follow-up and trends in breast augmentation in 527 transgender women and nonbinary individuals: a 30-year experience in Amsterdam. Journal of Plastic, Reconstructive and Aesthetic Surgery 2021;74(11):3158–3167. doi:10.1016/j.bjps.2021.03.107 ↗
3. Fakin RM, Zimmermann S, Kaye K, et al. Long-term outcomes in breast augmentation in trans-women: a 20-year experience. Aesthetic Surgery Journal 2019;39(4):381–390. doi:10.1093/asj/sjy143 ↗
4. Coon D, Lee E, Fischer B, et al. Breast augmentation in the transfemale patient: comprehensive principles for planning and obtaining ideal results. Plastic and Reconstructive Surgery 2020;145(6):1343–1353. doi:10.1097/PRS.0000000000006819 ↗
5. de Blok CJM, Klaver M, Wiepjes CM, et al. Breast development in transwomen after 1 year of cross-sex hormone therapy: results of a prospective multicenter study. Journal of Clinical Endocrinology and Metabolism 2018;103(2):532–538. doi:10.1210/jc.2017-01927 ↗
6. Adams WP, Small KH. The process of breast augmentation with special focus on patient education, patient selection and implant selection. Clinics in Plastic Surgery 2015;42(4):413–426. doi:10.1016/j.cps.2015.06.001 ↗
7. Kamali A, Sackey H, Gran I, et al. Implant attributes or patient characteristics? Factors affecting outcome after breast augmentation in transgender women. Plastic and Reconstructive Surgery Global Open 2022;10(11):e4645. doi:10.1097/GOX.0000000000004645 ↗
8. Rouhani DS, McLaughlin MF, Mehta N, et al. Structural and sociodemographic determinants of BREAST-Q outcomes after gender-affirming breast augmentation in transgender women. JPRAS Open 2026;50:506–517. doi:10.1016/j.jpra.2026.05.011 ↗

Related Articles

• MTF Top Surgery Recovery and Aftercare
• Does MTF Top Surgery Affect Nipple Sensitivity?
• Can You Have MTF Breast Augmentation Without Hormones?
• Breast Implant Sizes: How to Choose the Right Size