Sizing bamboo loungewear: how to check before you buy
Share
Buy the size you normally wear, then check two measurements against the size chart before you order: chest or bust, and hip. There is no legal definition of a Medium in the United States, so one brand's Medium is simply a decision that brand made. Our bamboo loungewear runs Small through XX-Large, and because it is 95% bamboo viscose with 5% spandex, it has real give — which makes the fit forgiving and also makes it easy to size down by mistake.
Nothing requires a Medium to be a Medium
The United States once had a federal voluntary standard for women's apparel sizing, PS 42-70, "Body Measurements for the Sizing of Women's Patterns and Apparel." It now appears on NIST's list of withdrawn Department of Commerce product standards. Nothing replaced it with force of law.
What exists instead is voluntary: ASTM publishes standard tables of body measurements, including D5585 for the adult female misses figure type in sizes 00–20 and D6240 for adult males in chest sizes 34–52. These are reference tables a brand may use. No brand has to. Most build their own grade from their own fit model, which is why your size is reliable within one label and unreliable across labels.
So the only number that means anything is the one on the product page's size chart, compared against your body. Everything below is how to do that in about a minute.
Measure two things, not six
How to measure for loungewear
Chest or bust. Tape around the fullest part, level all the way round, arms down. Wear a thin shirt, not a jumper, and do not pull the tape tight.
Hip. Tape around the fullest part of the seat, usually 7–9 inches below the natural waist, feet together.
Then. Find the row on the size chart where both land. If chest says Medium and hip says Large on a matched set, take the Large — the top has more room to spare than the pants do.
Inseam matters less here than in trousers, because lounge pants are cut long and worn barefoot or in socks.
Natural waist is not where your jeans sit. It is the narrowest part of your torso, roughly level with your elbow when your arm hangs straight. For a drawstring lounge pant it barely matters, which is the point: fewer measurements, fewer ways to get it wrong.
What the 5% spandex actually does
The men's bamboo lounge pajama set is 95% bamboo viscose, 5% spandex. That small amount of elastane is why the fabric moves when you turn over instead of winding round your legs, and why a set that measures slightly snug is still comfortable.
It is also the trap. Stretch lets a smaller size go on, so people size down, and then the waistband rolls and the shoulder seam sits inboard of the shoulder. Awake you does not notice that. Asleep you, lying on the seam for seven hours, does. For anything you sleep in, pick the relaxed size, not the size that technically fits.
Why there is no XS and no 3XL
Here is the unflattering part. The lounge sets we carry grade Small, Medium, Large, X-Large, XX-Large. That is five sizes. There is no XS at the bottom and nothing above XX-Large — not on the men's pajama set at $86.99, not on the women's long-sleeve and jogger set at $78.99, and not on the henley hoodie and fleece pants set at $116.99.
ASTM's men's table runs to a 52-inch chest. The grade on these sets stops well before that. We could list XS and 3XL on the page and let you find out at delivery; plenty of shops do. Instead: if you are outside Small to XX-Large, these sets will not fit you, and you should buy loungewear somewhere that actually cuts your size.
The range does go wider on one thing: the women's bamboo viscose boyshorts are graded Small through 5X-Large. A simple knit garment grades further than a cut-and-sewn matched set does. That is a property of the pattern, not generosity on our part.
Do not buy up for shrinkage
Buying a size up to leave room for shrinkage gives you a garment that is wrong now in the hope it will be right later. Viscose does change dimension, but what drives that is hot water and a hot dryer, not the passage of time. The care instruction on these sets is machine wash cold, tumble dry low, no fabric softener. Follow it and you are sizing for the garment you will keep wearing.
One labelling note while we are here: what feels like "bamboo fabric" is viscose — a regenerated cellulose fibre made by dissolving bamboo pulp. US textile labelling rules require the generic fibre name, so the label says rayon or viscose, and the FTC has acted against sellers who called it bamboo instead. It is a real fibre with real properties. It is just not bamboo in the way a bamboo cutting board is bamboo.
The five-second check before you order
1. Chest or bust measurement in hand.
2. Hip measurement in hand.
3. Both inside Small–XX-Large on the chart? If not, stop here.
4. Split between two sizes? Take the larger one.
5. Sleeping in it? Take the larger one anyway.
Where to look
All of the bamboo viscose loungewear, tees and socks sit in Clothing. If you are sizing a set for sleeping specifically, the sheets, toppers and pillows it goes with are in Sleep & Bedroom.
Sizes and prices above are what the store lists today. Check the product page for the current chart before ordering.