Blouse Size Calculator

How to calculate blouse size

A blouse size starts with three measurements. Your bust sets the main size, because a blouse must close and sit smoothly across the chest. Your waist and hips act as checks, because a blouse that fits the bust but pulls at the waist or hips will not sit right when tucked or buttoned. Your height helps with length, not with the letter size itself.

The calculator above follows the same logic. It finds a size from your bust, finds sizes from your waist and hips, and returns the largest of the three as your starting size. That rule protects the widest area the blouse covers. If your bust suggests medium and your hips suggest large, start with large and adjust the fit from there, rather than squeezing into medium and hoping the fabric gives.

Do not choose blouse size from bust alone

Bust alone misleads in two common ways. First, two people with the same bust can have very different waists and hips, and a blouse cut for one body shape will fit the other badly at the waistband or hem. Second, bust measurement changes with the bra worn underneath, so a measurement taken over a padded bra can push you a full size up for no good reason.

Measure over a thin, unpadded bra or a close-fitting top, stand naturally, and keep the tape level. Take the bust at the fullest point, the waist at the natural waist (usually just above the navel), and the hips at the fullest point. Write all three down before you open any chart, so you are not tempted to round the one number you remember best.

General blouse size chart

The chart below gives broad adult bust ranges in inches. Treat it as a starting range, not a brand size. Brands grade differently, and a blouse labelled medium by one brand can match a small or a large from another, so always check the brand chart for the blouse you are actually buying.

Read a row across, not down one column. Find your bust row first, then check whether your waist and hips fall in the same row. If they fall in a larger row, that larger row is your starting size. If they fall in a smaller row, stay with the bust row and expect extra room at the waist or hips, which tucking or a belt can handle more easily than a tight bust can be fixed.

How blouse shaping changes fit

Blouses are shaped, not just sized. Darts are short stitched folds that pull fabric in at the bust and waist, and princess seams run from the shoulder or armhole down through the bust to shape the front panel. A blouse with strong shaping follows your curves closely, which looks neat when it fits and pulls or gaps quickly when it does not.

An unstructured blouse, by contrast, hangs from the shoulders with little shaping. It forgives a waist that is a size off, but it can look boxy on a body with a large bust-to-waist difference, because the fabric falls straight from the widest point. When you compare two blouses in the same letter size, check the shaping first: the more shaped blouse needs the more accurate bust and waist measurements.

Fitted vs relaxed blouse fit

Fitted means the blouse follows the body with little extra fabric, usually with darts or princess seams and a defined waist. Relaxed means extra ease through the body, a straighter cut, and room to move without pulling. The same person often wears one size in a fitted blouse and the same size, or even a size down, in a relaxed blouse, because the relaxed cut already contains the extra room.

Choose fitted when you want a tucked, tailored look and you are confident in your bust and waist measurements. Choose relaxed when you want an untucked layer, when you are between sizes, or when the blouse has no stretch. The calculator above asks for fit for this reason: a fitted choice tightens the note it gives you when your bust sits near the top of a size range.

Sleeve length choices

Sleeve length does not change your body size, but it changes what a small error feels like. A short sleeve ends above the elbow, so a small length error is barely noticeable. A three-quarter sleeve ends below the elbow, which suits most arm lengths and hides a small error well. A long sleeve must reach the wrist bone without pulling at the shoulder when you bend your arm, so it is the least forgiving choice.

If you are between sizes and choosing a long sleeve, favour the larger size: the extra shoulder width gives the sleeve room to reach the wrist. If you are choosing a short sleeve, the body fit matters more than the sleeve, so follow the bust and waist result instead.

Blouse length and tucking

Blouse length is measured from the shoulder to the hem, and it decides whether the blouse tucks neatly, sits at the waistband, or covers the hips. A blouse meant for tucking needs enough length to stay tucked when you sit and reach, which is usually a couple of inches below the waistband. A blouse meant to be worn untucked should end near the hip, not halfway up the torso, or it will ride up and bunch.

Height changes this more than size does. If you are shorter, a standard length may cover more of your hips than intended, and a petite length may tuck better. If you are taller, a standard length may pull out when tucked, and a tall length may be worth looking for. The calculator gives a length note from your height for exactly this reason, but length is a guide, not a size change.

Button gaping and what it signals

Button gaping, where the front pulls open between buttons across the bust, is the clearest fitted-blouse warning sign. It almost always means the bust area is too tight for that cut, not that the blouse is badly made. The fix is usually the next size up, or the same size in a relaxed cut, rather than a smaller size pulled tighter.

Check the shoulders before you size up, though. If the shoulder seams already sit past your shoulder points, sizing up will drop them further and make the blouse look oversized everywhere else. In that case, look for the same size with more bust ease, a stretch fabric, or a different cut, rather than simply going larger.

What to do when between blouse sizes

Between sizes is normal, because bodies do not fall neatly on chart boundaries. Start with the larger size when the blouse is fitted, has no stretch, or buttons down the front, because a tight bust cannot be fixed by tucking or belting. Start with the smaller size when the blouse is relaxed, stretchy, or worn untucked, because the extra fabric already gives you room.

Then check the two places that cannot be adjusted easily: shoulders and bust. Shoulder seams should sit at your shoulder points, and buttons should close without pulling. Waist and hip room can usually be adjusted with tucking, a belt, or a simple alteration, but shoulders and bust cannot, so let those two areas decide.

Signs a blouse is too small

Buttons pull open across the bust, the fabric strains when you sit or reach forward, the shoulder seams pull inward toward your neck, or the hem rides up when you move. Horizontal creases across the chest or waist are another sign: they show fabric being pulled sideways because there is not enough width for the body underneath.

A blouse that is too small also feels restrictive in ordinary movement. If you notice yourself avoiding reaching overhead or sitting upright just to keep the blouse comfortable, the size is wrong, even if it looks acceptable standing still in a mirror.

Signs a blouse is too large

Shoulder seams drop past your shoulder points, the neckline gapes when you lean forward, the sleeves bunch heavily at the wrist, or the body hangs straight with no shape at the waist even in a fitted style. Vertical folds of excess fabric at the sides are the large-size equivalent of horizontal pull lines: they show fabric with nowhere to go.

A relaxed blouse will always carry some extra fabric, so judge a large size by the shoulders and neckline, not by looseness in the body alone. If the shoulders sit right and only the body feels roomy, the size may be correct for a relaxed cut, and tucking or a belt may be all it needs.

How to choose blouse size online

Online, you cannot try the blouse on, so your measurements carry the whole decision. Measure first, then open the brand's own chart and find your row there, not on a general chart. Check whether the chart lists body measurements or finished garment measurements: garment measurements already include ease, so comparing your body to a garment chart will push you a size too large.

Read the fit notes on the product page as well. Words like fitted, tailored, relaxed, oversized and boxy describe ease, and they change what the same letter size feels like. Check the return policy before ordering between sizes, and when in doubt between two sizes in a fitted, non-stretch blouse, order the larger one first, since a slightly loose blouse is easier to adjust than a gaping one.

Common blouse-sizing mistakes

The most common mistake is measuring over a padded bra or a thick sweater, which inflates the bust and pushes the whole result up. The next is using an old size from memory: bodies change, brands revise their grading, and a size that fitted two years ago may not fit now. The third is comparing your body measurements to a garment measurement chart, which double-counts ease. The fourth is ignoring the waist and hips and choosing from bust alone, which is how a blouse ends up fitting the chest and pulling everywhere else.

Re-measure every six to twelve months, and whenever you notice fit problems appearing in blouses that used to fit. Keep your three numbers written down, and re-check them against the brand chart each time you buy from a new brand, rather than assuming your usual size travels with you.

Frequently Asked Questions