Nightgown Size Guide: How to Measure, Step by Step

Choose a nightgown size by measuring, not guessing. Take your bust, waist and hip measurements with a tape measure, and measure your length too if you are considering a long style; then compare the numbers with the size information on the product page. In strappy and bias-cut nightgowns, the most important measurement is usually the hips.

Why your usual size doesn't always fit

Size letters vary from brand to brand; an S in one can come up as an M in another. The fabric matters too. A knitted cotton nightdress stretches and forgives; woven silk doesn't stretch. A bias cut gives a little ease, but not enough to cover a full size. In short, trust centimetres rather than letters, and compare your measurements again for every new style.

Before you measure

• A tailor's tape: a flexible fabric or plastic tape. A metal tape measure won't follow the body.
• A mirror or a helper: to make sure the tape doesn't drop at the back, especially for hips and length.
• Light clothing: measure in thin underwear or nothing at all. Measuring over thick clothes gives numbers that are too big.
• Notes: write each number down straight away; keeping three numbers in your head is harder than it sounds.

Stand straight with your feet together rather than shoulder-width apart, and breathe normally. Don't pull your stomach in or push your chest out. Your waist can change slightly through the day; if you want to be sure, measure again at a different time.

How to measure, step by step

Bust

Run the tape around the fullest part of your bust, under your arms. At the back it should sit straight, just below the shoulder blades, without riding up. Don't pull it tight; you should be able to slip one finger between the tape and your skin. For a strappy nightdress, measure the way you will wear it: if you will go braless, measure without a bra.

Waist

Find the narrowest part of your waist; for most people it is slightly above the navel. If you can't find it, bend gently to the side: the crease that forms marks your waist. Keep the tape parallel to the floor and relaxed.

Hips

Put your feet together and run the tape around the widest part of your hips and seat. Check sideways in the mirror: the tape shouldn't drop at the back. If you are unsure, measure at a few different heights and write down the largest number. This is the number you will need for a bias cut.

Length

For long nightdresses and slip dresses, length is decisive. With a helper, measure from the top of your shoulder, where the strap will sit, down to the floor. On your own, lay a long dress that fits you well flat and measure from the top of the strap to the hem. When you compare with the length on the product page, think about whether you walk around barefoot or in slippers at home.

Which measurement decides: by cut

• Bias-cut, strappy nightdresses and slip dresses: the fabric sits close at the hips and stomach. Choose by your hip measurement. If bust and hips fall in different sizes, take the larger; you may have a little room at the bust, but tight hips in a bias cut are far more uncomfortable.
• Dress-cut nightdresses that flare at the hem: the hips have more room, so the bust measurement leads.
• Pyjama sets: bust for the top, hips for the bottoms. An elastic waist stretches, hips don't; choose the bottoms by your hips.
• Robes and kimonos: because they tie with a belt, the waist hardly matters. Bust, shoulder width and sleeve length decide.

Small adjustments for your proportions

• If your bust is a size bigger than your hips: in a strappy style, a size that is tight at the bust strains the straps and opens the neckline. Choose by your bust, or look for a V-neck style with room at the bust.
• If your hips are a size bigger than your bust: choose by your hips. A little extra room at the bust rarely shows in a thin-strap style.
• If you are tall: always check the length on long styles. Sizing up adds a little length but noticeably more width; don't size up for length.
• If you are petite: an ankle-length style may touch the floor. A short nightdress or a below-the-knee length is less of a risk.

Body measurements or garment measurements?

Size information shows two kinds of numbers, and it is important not to mix them up. Body measurements tell you which bust, waist and hip circumference a size is meant for; you compare them directly with your own. Garment measurements describe the piece itself, usually given as the width laid flat from side to side. Multiply that number by two to get the circumference.

Garment measurements are always a little bigger than body measurements; the difference is ease, and it varies with the cut. In a bias-cut nightdress the ease is small and the fabric stays close to the body. In a loose robe it is generous. If garment measurements are given, don't choose a size that leaves no ease at all over your own measurement; woven silk needs a little room for sitting down and getting up.

If you are between two sizes

With silk the rule is simple: avoid the tighter size. A bias-cut nightdress that is tight at the hips rides up when you sit, strains the seams and tires quickly. A nightdress one size up falls a little looser, and silk carries that well.

The exception is narrow shoulders. If you are slim with narrow shoulders, the straps of a larger strappy style may slip off. In that case compare the product page measurements with your own one by one; if you are still unsure, check our FAQ or write to us.

Sizing at JANESIA

The JANESIA silk nightdresses, the slip dress and the women's pyjama sets run from XS to XL. The Kimono comes in two broader ranges, S/M and L/XL; with its belt and loose cut, that is enough. Size information is on each product's own page. Because the styles have different cuts, don't carry your size straight from one style to another; check the page each time.

Two examples: the Long Slip Dress is bias-cut and ankle-length, so your hip and length measurements come first. The Lace Nightdress is short and dress-cut; length isn't an issue, and bust and hips are read together. All styles are in the nightdresses collection. We cover cut and length separately in how to choose a silk nightgown.

Buying a gift without knowing the size

Buying a nightdress without knowing the size is risky, but there are a few ways round it. Look at the label of a well-fitting dress in her wardrobe, or lay that dress flat, measure the width at bust and hip level and multiply by two. It is a rough estimate, but better than nothing. If you can't be sure at all, go for a piece that depends less on size: a belted kimono or robe tolerates a sizing mistake far better thanks to its loose cut. The differences are in robe vs kimono. Box and note options for gifts are on the gift page.

The most common measuring mistakes

• Pulling the tape tight: the number comes out small and the nightdress fits tight.
• Measuring over clothes: the number comes out big and the nightdress fits loose.
• Letting the tape drop at the back: it makes a difference, especially at the hips.
• Looking only at the size letter: misleading because sizes differ between brands.
• Using your waist measurement instead of your hips: the most misleading mistake in a bias cut.
• Carrying the size of a stretchy cotton nightdress over to woven silk.