Three sizes is the normal answer
A pattern company drafts one body — a single set of proportions — and then grades it up and down to make a size range. Everyone in that range has the same proportions as everyone else in it. Almost nobody outside the drafting room does.
So you measure, and the chart hands you a 16 at the bust, a 12 at the waist and a 14 at the hip. Nothing has gone wrong. You are simply not the shape the chart was drawn from, and neither is nearly anyone else. This is the single most common reason people give up on sewing patterns, and it is entirely fixable.
What you do about it is called blending
You cut the bust line at one size and curve gradually across to another size at the waist, and out again to a third at the hip. It happens on the side seam, over three or four inches, and it is drawn with a pencil rather than calculated. On the pattern piece it looks like a diagonal.
The one rule worth knowing: for anything with a bodice, start from the bust. The shoulders and the armhole are cut from the same size as the bust, and they are the hardest things on a garment to change afterwards. For trousers and skirts, start from the hip instead. Blending between sizes shows it drawn out.
Your pattern size is not your shop size
Shop sizes have crept smaller for sixty years. Pattern sizes have barely moved since the 1960s. The result is that people routinely measure two, three or four sizes larger on a pattern envelope than on a shop label, decide they have measured wrong, and cut too small.
You have not measured wrong. The number is a coordinate on somebody's chart, it is different on every chart, and once the garment is made nobody can see it.
A 16 in one brand is not a 16 in another
Every company publishes its own body chart, and they genuinely differ — sometimes by two full sizes at the same measurement. Some publish more than one chart at a time: Closet Core drafts one block for sizes 0 to 20 and a separate one for 14 to 32, and a 14 in one is not a 14 in the other. Merchant & Mills has an older grade still printed on much of its back catalogue.
That is why this page asks which brand before it answers, and why the sizes change when you press a different button.
What this page does not do
It reads three measurements off a body chart. It does not know about:
- Ease — how much room the designer added beyond the body. A shirt and a coat at the same bust measurement are very different garments. Ease, explained.
- A full bust adjustment. Most patterns are drafted for a B cup. If you are fuller than that, the right move is usually to cut a smaller size from your high bust and add the difference back at the bust point — which needs a measurement this page does not ask for.
- Height. Most of these charts are drafted for someone about 5 ft 6 in, and the bodice and trouser lengths follow from that.
All three are in the full calculator, along with a blending diagram drawn to your own numbers.
And then sew a muslin
No calculator replaces a test garment in cheap fabric. What this page does is stop your first muslin from starting at a guess.
Print the chart you are working from
The table below is the published body chart for the brand you have selected, with your own sizes marked. It changes when you press a different brand.