Weighted Blanket Calculator

A weighted blanket is a blanket filled with glass beads, plastic pellets or chains, so it presses gently on your body. Most people pick one by taking about 10 percent of their body weight. This calculator applies that rule, then rounds to a size sold in stores.

What the 10 Percent Rule Measures

The 10 percent rule is a sizing convention, not a health measure. Manufacturers' instructions usually say a weighted blanket should not be more than 10 percent of the user's weight¹. The rule traces back to a 2008 position statement by Quebec's order of occupational therapists. It set a 10 percent limit for children after a judicial review into the death of a child who suffocated under a weighted blanket². So the number began as a safety ceiling, not as a dose shown to improve sleep.

The Formula

Target weight = body weight x 0.10

Recommended blanket = the largest standard size that is not above the target

Standard sizes = 5, 7, 10, 12, 15, 20 and 25 lb

How This Calculator Computes Your Result

Enter your body weight in pounds or kilograms. Kilograms are converted to pounds (1 kg = 2.20462 lb). The tool takes 10 percent, rounds it to one decimal, and picks the largest standard size at or below that number. It also shows what percent of your body weight the blanket is, and the next size up if you fall between two sizes. If you choose a bed size, you also get a typical blanket size for it. Your bed size never changes the weight.

What Your Result Means

If you weigh 185 lb, 10 percent is 18.5 lb, which falls between the 15 lb and 20 lb sizes. The calculator shows 15 lb, because the rule is a maximum. That is 8.1 percent of your weight. A 20 lb blanket would be 10.8 percent. If 10 percent of your weight is more than 25 lb, the tool still shows 25 lb, which stays within the rule. The tool gives no result below 50 lb, since that is almost always a child.

Choosing a Blanket Size for Your Bed

A weighted blanket is meant to cover your body, not the whole bed¹⁰. It is smaller than a normal comforter and should not be tucked in or draped over the sides¹⁰. Typical sizes are about 38 by 72 inches for a twin, 60 by 80 inches for a queen, and 80 by 86 inches for a king¹⁰. A queen size suits most people sleeping alone¹⁰. A king blanket for two people has about 43 percent more area than a queen. So the same weight feels lighter on each person.

What the Research Says

The best known trial tested chain blankets in 120 outpatients with insomnia and a psychiatric condition such as depression, bipolar disorder, anxiety or ADHD³. After four weeks, 59.4 percent of the weighted blanket group had at least halved their insomnia score, compared with 5.4 percent of the light blanket group³. The blanket weight was not based on body weight. Everyone tried an 8 kg (17.6 lb) blanket, and 10 of 64 people switched to 6 kg (13.2 lb) because it felt too heavy³.

Reviews are more cautious. A 2020 systematic review of 8 studies found weighted blankets may ease anxiety, but the evidence was not enough to show they help insomnia⁴. A 2024 meta-analysis of 8 trials (426 patients) found a small drop in anxiety, but the pooled effect on insomnia did not reach significance⁵. About half of those trials had a high risk of bias, and none reported serious side effects⁵.

Who Should Not Use a Weighted Blanket

• Babies: The American Academy of Pediatrics says weighted blankets, sleepers and swaddles should not be placed on or near a sleeping infant⁶. The CPSC also says not to use them for babies⁷.

• Young children: In 2022, two girls aged 4 and 6 died after becoming trapped in the cover of a 6 lb children's weighted blanket, which led to a recall of about 204,000 units⁸. Occupational therapy guidance says a child must be able to free themselves and should never be left alone under one².

• Anyone who cannot push it off: This includes people with weakness, limited movement or reduced alertness¹.

• People with breathing, heart or circulation problems: Occupational therapists list breathing and heart problems, epilepsy and circulation problems as reasons not to use one². A Cleveland Clinic article notes that experts advise people with breathing problems such as sleep apnea to avoid them⁹.