The best cardigan size is not always the letter printed on the label. A medium in one pattern can have a very different finished circumference from a medium in another. Start with the body measurement, the amount of room you want and the pattern’s finished schematic.
Separate body size from garment size
If your chest measurement is 98 cm and the cardigan finishes at 110 cm, it has 12 cm of positive ease at that point. A finished measurement smaller than the body would be negative ease. Whether either choice feels right depends on the fabric and the intended style.
Measure a cardigan you already like while it lies flat and relaxed. Note how it is fastened and whether its front bands overlap. That reference can help you decide how much room you actually enjoy.
Read the schematic before the size name
Check the finished chest, upper arm, sleeve length, armhole depth and body length. A size can fit around the chest but still have sleeves that are too narrow or shoulders that sit differently from the design you expected.
Confirm whether a measurement is a full circumference or a flat width. A 55 cm flat chest width may correspond to roughly 110 cm around, but front openings and overlapping bands can affect how the designer reports it.
Match the actual pattern stitch
Make the stated gauge sample in the stitch and construction used for the garment. A plain double-crochet sample will not necessarily predict the width of a textured or colourwork cardigan. Care for the sample as directed before measuring.
For example, a 100-stitch panel at twenty stitches per 10 cm measures 50 cm. At eighteen stitches per 10 cm, the same panel measures about 55.6 cm. That difference is large enough to change the whole fit.
Check row gauge as well as stitch gauge
Stitch gauge controls width, while row gauge often affects length and shaping. If a sleeve increase occurs every fourth row, a different row height changes the distance between increases even when the stitch gauge matches.
Do not adjust body length casually where the pattern includes armholes, waist shaping or a fixed colourwork chart. Identify which straight section can be changed without moving a structural feature.
Allow for bands, seams and the fabric’s weight
Front bands and collars can add width or change how the cardigan hangs. Seams can take up a small amount of fabric and limit stretch at particular points. Read whether the finished measurements include those elements.
A large crochet garment also hangs under more weight than a tiny sample. Use a sufficiently generous swatch and inspect the fabric’s drape. If the pattern provides advice about blocking or hanging gauge, follow that method.
Write a size decision you can check later
Record the chosen pattern size, body measurements, intended ease, washed gauge and any planned length adjustment. Mark the relevant numbers in multi-size instructions before beginning.
For a first cardigan, choosing a pattern close to the desired fit is usually easier than rewriting several areas at once. The aim is a garment whose dimensions you understand, not merely a size name that sounds familiar.
Continue learning
Understand hexagon construction · Sample a different garment fabric · Plan a seam
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