How Much Do 400 Cc Breast Implants Weigh?

I'm 5'7, 116 pounds and currently have a 34 A/B cup. I read online that one way to find out how big I should go was the birdseed-in-a-nylon route. After doing cup to cc conversion it came out to around 400cc's. The problem is, wearing the birdseed around got my neck and shoulder's quite sore. I'm worried that it will be the same with implants. Has anyone else complained of back/neck pain after implants?

Doctor Answers 9

400cc Saline Breast Implants Weighs 400grams

It’s not unusual for prospective breast augmentation patients to worry about the weight of their new breast implants. They worry that breast enlargement may create some of the symptoms that are frequently associated with breast hypertrophy such as back and neck pain.
In this case a 400cc saline breast implant weighs 400 grams. There’s 454 grams in a pound so these implants weigh about .88 pounds. When silicone implants are used they weigh approximately 15% more than saline implants.
Implants in this size range are easily tolerated by most patients and aren’t associated with back or neck pain. This is especially true when implants are placed beneath the muscle. Under these circumstances, the muscle produces added support for the implant.
If you’re concerned about the weight of your breast implants, consultation with a board-certified plastic surgeon is appropriate. This surgeon should be able to discuss this issue and alleviate your concerns.

Neck and back pain uncommon

Now that you have tried on sizers and chosen a volume that you like, you can calculate the weight of the implants.  The density of water is 1 gm/cc, so a saline implant that is 400 cc will weigh approximately 400 gm.  Two 400 cc implants will weigh 800 gm.  The conversion from gm to lbs is 2.2 lbs/kg.  So the implants will weigh approximately 0.8 kg x 2.2 lbs/kg = 1.76 lbs.  However, the implants are typically under the muscle and held close to your center of gravity.  They will not weigh on your neck like the birdseed does in the sizers.  People typically do not complain of back or neck pain after breast augmentation.

Any weight increase can pull you downward.

Breast implants generally do not contribute significantly to weight increases. For example, a 400cc silicone breast implant weighs 424gm or 15 ounces (roughly two pounds for a pair). 

Perhaps you'll be happy with a smaller size, so the best way to know the right thing to do is to go in for a consultation with your Board Certified Plastic Surgeon.

Hope this helps.

Best of luck.

Brian K. Brzowski, MD
Ogden Plastic Surgeon
5.0 out of 5 stars 62 reviews

How Much do Breast Implants Weigh?

Dear Grand Canyon Girl,

Breast implants weigh about one gram per cc, so a 400 cc implant weighs about 400 grams, or 0.88 pounds. It is uncommon for breast implants to cause neck or back pain.

Warmest wishes,

Larry Fan, MD

Larry Fan, MD
San Francisco Plastic Surgeon
4.5 out of 5 stars 14 reviews


As an approximation 1 cc equals one gram, so 400 cc's equals 400 grams. 
In pounds this would be about  0.88 pounds per implant

Larry S. Nichter, MD, MS, FACS
Orange County Plastic Surgeon
5.0 out of 5 stars 107 reviews

Calculating The Weight Of Breast Implants

The weight of breast implants varies slightly based on whether they are saline or silicone. For saline implants, or water weight, 400cc roughly equals 400 grams or just under a pound. (specifically it is 1.7 lbs for both 400cc salinje breast implants) Silicone implants will weight slightly more than saline but only by about 15%. (1.9 lbs for both 400cc silicone implants) For implants of this size, I have never seen or heard of a patient complaining of symptoms that are more typical of large breast reduction patient discomfort. This is because in breasts that sag or hang, they pull on the neck and back just like a rope around your neck with small weighted sacs attached to them. In the breast augmentation patient, the implants and breasts are up on the chest wall and not suspended or hanging. Pain, shoulder and neck pain from breasts is as much as their position on the chest wall as it is their size and weight.

Weight of an implant

Thank you for a very interesting question. In short, for the same volume, the implant is likely to be lighter than birdseed, i.e. birdseed will be denser than silicone/saline implants.

I am surprised to hear about  soreness of neck and shoulder. I cannot recall a patient ever complaining about this after even larger implants. I can only suggest that you try with 400g of weight on each side and if you still have any problem, consider smaller implants.

Anindya Lahiri, FRCS (Plast)
Birmingham Plastic Surgeon
5.0 out of 5 stars 22 reviews

How much does 400cc weigh

this is any easy way to estimate the weight. 30cc's is 1 oz. So 400 cc's would be approximately 13 oz.

Remember that this is 13oz per breast.  16oz is how much is in a bottle of soda.

Jack Peterson, MD
Topeka Plastic Surgeon
4.5 out of 5 stars 31 reviews

How Much do Implants Weigh?

Implants weigh about 1 gram for every cc.

A 400 cc implant weighs about 400 grams or .88 lbs.

A pair of 400 cc implants weighs about 1 3/4 pounds.

Joseph Mele, MD
Walnut Creek Plastic Surgeon
4.5 out of 5 stars 12 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.