A Cup to C Cup Breast Implants: How Many CCs?
If you're currently an A cup and want to become a C cup after breast augmentation, how many cubic centimeters (cc) will you need? Research suggests that approximately 260cc to 300cc can represent two cup-size increments, but that is only a general starting point—not a reliable prediction of your final bra size. Your band size, natural breast tissue, chest dimensions, and implant shape all influence the outcome.
The important question isn't simply how many CCs equal a C cup. It's which implant dimensions can safely achieve the appearance you want on your particular body.
How Many CCs Does It Take to Go From an A Cup to a C Cup?
A 2017 study published in Plastic and Reconstructive Surgery investigated the relationship between implant volume and bra cup size. Researchers examined bra volumes across three manufacturers and studied 79 women who underwent breast augmentation.
Drag the slider to compare the appearance without sizers and with 350cc Oumènta breast implant sizers. External sizers do not predict surgical results.
The researchers found a mean increase of approximately 138cc per cup-size increment in the clinical group. Their findings suggested approximately 130cc to 150cc for a one-cup-size increase, although they also documented differences between bra manufacturers.
Applying that finding to two cup-size increments produces an illustrative range of approximately 260cc to 300cc. However, the study did not establish that every woman starting with an A cup will become a C cup with an implant in this range.
Read the 2017 study by King and colleagues.
"A C cup is a clothing size, not a specific breast implant volume."
Why Your Starting Bra Size Matters
Consider two women who both wear an A cup. One wears a 32A and the other a 36A. Although the cup letter is identical, the actual cup capacity differs because bra sizing is related to band size. Their chest dimensions, existing breast tissue, and desired proportions may also be different.
This is why a 300cc implant cannot be expected to produce the same result on every woman. The American Society of Plastic Surgeons also emphasizes that implant volume does not translate directly into a guaranteed bra cup size.
Read the American Society of Plastic Surgeons' guidance on implant selection.
What Would 250cc, 300cc, or 350cc Look Like?
These are useful volumes to explore when researching an A-to-C augmentation, but none is automatically the correct choice.
250cc: The smallest of these three options. Compare how this volume changes your silhouette in a fitted shirt versus a loose top, especially if you're hoping for a relatively subtle increase.
300cc: Adds 50cc per breast compared with 250cc, a 20% increase in sizer volume. That does not mean your breasts will appear 20% larger, but the difference may be noticeable when you try both sizes.
350cc: Adds another 50cc per breast compared with 300cc. Compare the front and side views, remembering that chest width, natural tissue, and clothing all influence how much fullness is visible.
Instead of deciding from a chart alone, compare how these volumes appear with your own proportions and clothing. Pay attention to the front view, side profile, and how your preferences change between fitted and loose-fitting outfits.
For another perspective on smaller volumes, read our article What Do 200cc Breast Implants Look Like on Me? You can also explore our 350cc vs. 450cc breast implant comparison to understand how a larger difference in volume may appear.
Try the Breast Implant Size Calculator
Oumènta's Breast Implant Size Calculator offers a starting point for exploring different breast implant volumes.
The calculator helps you narrow down sizes to consider based on the information you provide. Its suggestions are educational estimates, not clinical recommendations. It cannot examine your breast tissue, measure your breast base width, or determine which implant your anatomy can safely accommodate.
Once you have a starting range, you can compare external sizers to better understand your appearance preferences before discussing your goals with your surgeon.
How Accurate Are Breast Implant Sizers?
External breast implant sizers can help you explore the appearance and feel of different volumes under clothing. But they cannot reproduce the result of surgically placed implants.
A 2017 study by Costa, Small, and Adams, published in Aesthetic Surgery Journal, compared external silicone implant sizers worn in surgical bras with three-dimensional surgical simulations.
Among seven women, the researchers found that the bra/sizer images had an average measured volume 22.3% greater than the corresponding simulated images. They also identified differences in upper breast fullness and projection.
There are important limitations. The study was small, compared external sizing with computer simulations rather than directly measuring postoperative outcomes, and did not evaluate Oumènta products. Its findings should not be interpreted as a universal correction factor for external sizers.
Read the 2017 external sizing study.
The practical takeaway is to compare several volumes rather than treating any one external sizer as an exact prediction. Try a smaller and larger size, observe how each looks under your everyday clothing, and share those preferences with your surgeon.
Oumènta's Pocket Bra has a snug, supportive fit designed to hold external sizers in position during everyday activities. It is not a clinically validated simulation of breast augmentation.
For a practical example of external sizing, see our 325cc Breast Implant Sizers: Before and After article.
How to Explore Your Preferred Size at Home
The Oumènta breast implant sizer kit includes a pocket bra and three pairs of external sizers in your selected volumes. Available sizes range from 200cc to 500cc in 25cc increments.
For example, you could compare 250cc, 300cc, and 350cc in the same bra. Try each volume with a fitted shirt, a looser top, and your everyday clothing. Examine your appearance from the front and side, and take notes about what you prefer.
If you're considering a larger size as well, our article What Would 400cc Breast Implants Look Like on Me? explores how body proportions influence the appearance of 400cc.
This experience is intended to help you communicate your aesthetic preferences. It does not establish which implant volume, profile, or placement is medically appropriate for you.
Frequently Asked Questions
Will 300cc implants take me from an A cup to a C cup?
Possibly, but there is no guarantee. A 300cc implant may produce different cup sizes and appearances depending on your band size, existing tissue, chest measurements, and implant dimensions.
Is 250cc enough to go from A to C?
It may be for some women, but cup-size conversion is not precise enough to predict that outcome. Your surgeon can evaluate your anatomy and explain what is realistic.
Does a C cup look the same on everyone?
No. A 32C and a 36C have different cup capacities, and the same bra size can appear different depending on body proportions and breast shape.
Can a breast implant size calculator tell me exactly what I need?
No. A calculator can suggest volumes to explore, but it cannot perform a physical examination or determine a medically appropriate implant size.
Should I choose my implants based on cup size or CCs?
Use your desired cup size to help explain your goals, but also discuss the appearance you want, implant width and projection, and your anatomical measurements with your surgeon.
The Bottom Line
If you're hoping to go from an A cup to a C cup, research provides a useful starting point for understanding volume—but not a guaranteed conversion. Explore different sizes, identify the appearance you prefer, and bring those observations to your plastic surgeon.
Medical disclaimer: This article is for general education. Oumènta breast implant sizers are external apparel products, not medical devices. Neither external sizers nor the Oumènta calculator can predict surgical outcomes or replace an examination and consultation with a qualified plastic surgeon.
Recommended Breast Implant Sizer Kit
Experience three different sizer volumes at home before discussing your preferences with your surgeon.
