The Weighted Blanket’s Size and Weight
The most frequently asked question concerning weighted blankets is “How do I know what size or weight blanket to get for my child?”. Unfortunately, the response that is typically provided, whether by well-meaning friends, family members or medical professionals is based on a common misunderstanding.
The “Ten Percent Myth”
Whether you’ve scoured the internet, requested information from companies that manufacture weighted blankets or discussed the topic with medical professionals, you probably ended up with a “formula” that goes something like this: “Take 10% of the user’s weight and add 1 to 2 pounds in order to get the correct blanket weight.”
The problem with this formula is that it does NOT come from any studies on weighted blankets, but seems to be an extrapolation from one or more papers where the researchers were studying the relationship between back injuries and the weight of backpacks used by school children, and in those papers, the notion of a backpack being 10% of the child’s weight was a safety limit beyond which injury may occur and not a recommended weight for use.
There is a simpler and much better method however which can make the whole process easier.
A Matter of Preference
For healthy adults, both the weight and the size of a weighted blanket is simply a matter of preference. There are of course, some caveats, but in general if the person using the blanket has full use of their faculties, can move and breath without any problems and is fully conscious then it’s nothing more complicated than preference.
We have found that many of our customers enjoy a really heavy blanket because it feels like a giant bear hug while for others that same heavy blanket may actually increase their anxiety level and so they prefer something lighter.
What Constitutes Light vs. Heavy?
Each size blanket is available in a range of weights. In general, the available weights are driven by the size of the squares in the blanket, how many pellets can comfortably fit in each square and finally the size of the blanket itself.
For example, in a small blanket (37” x 52”) there are 70 squares, each one being 5” x 5”. In each square you can put a maximum of 60 grams of plastic pellets. So, 60 grams times 70 squares (doing conversion in my head) equals roughly 9.5 pounds. In a larger blanket like a king size, you can, of course, fit more pellets and make it even heavier.
Pressure to the Rescue!
One last thing we haven’t discussed yet is the fact that weight alone really isn’t sufficient. For example, imagine you have two different blankets, one small and the other king sized, each one filled with 6 pounds of pellets.
Even though they have the same amount of weight, the king-sized blanket will feel lighter because the 6 pounds of pellets are spread over a much wider area and only a relatively small portion will be in the part of the blanket that is on your body. The small one will feel heavier for exactly the opposite reason.
This is why the 10% formula doesn’t work. Imagine I weigh 110 pounds. Using the formula, I arrive at a “recommended” weight of 12-13 pounds, but in what size blanket? That same weight will feel very different in a small, queen or king size blanket. See the problem?
Using pressure instead of a simple static weight eliminates this problem because it allows us to select a weight that feels the same regardless of the blanket size. The pressure I am referring to here, is the weight of the pellets per square foot of blanket.
So, in my previous example, the 12 pounds in a small blanket (37 x 52) comes out to 0.89 pounds per square foot but in a king size blanket (76 x 82) it comes out to only 0.27 pounds per square foot.
By using pressure, we can find a weight that feels the same regardless of the size of the blanket. For example, if I want a blanket that is 0.52 pounds per square foot, then I can choose either a small blanket at 7 pounds or a king size blanket at 22 pounds and get roughly the same feel.
For those who enjoy math … the small blanket is 37 x 52 and therefore 37 inches times 52 inches equals 1924 square inches. Divide that number by 144 to convert to square feet and we get 13.36 square feet.
If we want to know how many pounds for a specific pressure we simply multiply the square feet by the pressure we want to get the # of pounds.
13.36 times 0.52 = 6.94 pounds of pellets
If we want to know how much pressure a specific weight will be, we divide the weight by the square footage of the blanket.
2 pounds divided by 13.16 gives a pressure of 0.89 pounds per square foot
The range of our blankets tends to run from 0.30 - 0.95 pounds per square foot with most of our adult customers preferring something around 0.65 on average. The smaller blankets which are more appropriate for a child tend to have a lower maximum pressure.
Children occasionally need their personal preferences constrained for safety reasons. Weighted blankets for children should be just large enough to cover the child but not excessively large to the point that the amount of weight required to be effective becomes a safety hazard. The last thing you’d want is for a young child to find themselves stuck under a 30-pound blanket.
There are certain medical conditions that also warrant special consideration in both children and adults. Anyone considering the use of a weighted blanket who is dealing with a condition that restricts breathing, results in difficulty of movement or loss of muscle strength such as COPD, muscular dystrophy, multiple sclerosis, seizures, etc. should always consult with a medical professional before using a weighted blanket. In addition, normally healthy adults who are taking medications which make them drowsy or disoriented should not use their weighted blanket without specific instructions from their physician. Similar precautions should also be taken with the elderly.
As of the writing of this article I know of no scientific studies available to determine what constitutes a safe weight or pressure in children, therefore common sense and consultation with a medical professional should prevail.
How do I Know my Preferences?
This is a great question, especially if you are making your first purchase of a weighted blanket. There are at least two options you might try.
- The simplest one is to choose a size for the blanket and then take the weight that is in the middle of the range for that particular size.
- The second option involves taking regular blankets or quilts from your house and laying down on the bed while someone keeps adding more blankets until it feels comfortable and soothing for you. (PS …try it for several minutes so you are sure it isn’t too heavy). Once you know how many regular blankets it takes to make you feel comfortable, you can add up their weight, calculate the pressure from each blanket and simply add up the pressures.
So, for example, if you need to put 3 regular blankets on in order for it to feel soothing and the blankets have the following pressures (0.14, 0.08, 0.17) you would add them up for a total of 0.39 you then know that whatever size weighted blanket you decide on, it should have a weight which produces 0.39 pounds per square foot of pressure.
- NEVER use a weighted blanket as a punishment or restraint
- NEVER use a weighted blanket in a crib or bed with rails
- NEVER use a weighted blanket with a person who is unconscious or unable to remove the blanket from their face
- NEVER use a weighted blanket with a child under 3 years without consulting a medical professional
- NEVER let children use a weighted blanket as a tent or for playing hide and seek
- A weighted blanket is a wonderful thing, but using it safely is of paramount importance. The examples given in this article are just that, examples. They are not intended to provide a complete or comprehensive list. If you have any questions or concerns at all, you should consult a medical professional before using a weighted blanket.
- You should ALWAYS consult with a medical professional before using a weighted blanket on a child or if there is any concern over safety.