Main width measurements
Chest controls upper width; hips or hem width control the lower opening. Ease can be positive or reduced for stretchy knit fabric.
Sewing pattern guide
T-shirt measurements guide
A T-shirt draft depends on body measurements and knit fabric behavior. Neckline, armhole, sleeve, and neckband compatibility are especially important.
A T-shirt looks like the simplest garment to measure for, and that is exactly why so many self-drafted ones fit badly: because knits stretch, people assume the numbers barely matter. In fact the opposite is true — since the T-shirt generator drafts for knit fabric with far less ease than a woven pattern, sometimes zero or negative, there is no spare room to hide a sloppy chest or bicep reading. The measurements and the fabric's stretch have to be judged together.
This guide covers the eight body measurements the generator asks for — chest, waist, hips, T-shirt length, shoulder width, armhole depth, bicep, and sleeve length — plus the one measurement most tutorials skip: the stretch percentage of your actual fabric, which decides how much ease you should enter. The generator drafts front and back pieces cut on the fold, a sleeve whose cap is matched to the armhole, and a neckband already shortened relative to the neckline.
You will need a flexible tape measure and a mirror; a helper makes the shoulder and armhole values more reliable. Measure over bare skin or one thin layer, in centimetres. If you already own a T-shirt that fits the way you want, keep it nearby — comparing its flat widths against your generated pieces is the fastest sanity check available.
Use this guide
Related pattern templates
Open a matching generator after reviewing the guide, then preview the calculated draft before export.
Generator
T-shirt pattern
Generate front, back, sleeve, and neckband pieces for a knit T-shirt draft.
GeneratorBasic sleeve pattern
Generate a sleeve block and check cap shape, bicep, wrist, and armhole compatibility.
GuideSeam and hem allowances
Review solid lines, dashed cutting lines, seam allowance, and larger hem allowance.
Body length
Shirt length changes where the hem sits and how much room is needed at the hips.
Shoulder and armhole
Shoulder width positions the armhole. The armhole curve should be smooth and compatible with the sleeve.
Sleeve length and cap
The sleeve cap must match the T-shirt armhole, and sleeve length must match the chosen style.
Round or V neckline
A round neckline should curve smoothly; a V neckline should meet at a clean point and still connect clearly to the shoulder.
Neckband length
The neckband is usually shorter than the neckline on knit fabric, but the exact amount depends on stretch and recovery.
Before cutting fabric
After generating a T-shirt, check front/back shoulder seams, armhole and sleeve cap match, neckline shape, neckband length, stretch direction, hem allowance, and fabric recovery.
Step by step
How to take each measurement
Find the high shoulder point first — the small bump where the base of the neck meets the shoulder line. The length, shoulder, and armhole measurements all reference it. Stand relaxed with arms down; a lifted arm changes the chest and bicep readings.
-
01
Chest
Measure horizontally around the fullest part of the chest or bust, tape level front and back, snug but not compressing. Breathe out normally before reading. This value plus the chest ease you choose sets the width of the front and back pieces — on a knit there is no dart to absorb an error, so 3 cm too small here is 3 cm too tight everywhere above the waist.
-
02
Waist and hips
Take the waist at the narrowest point of the torso and the hips around the fullest part of the seat. For a T-shirt, the hip value matters most when the shirt is long enough to reach it: together with hem ease it sets the hem opening. If your hips are wider than your chest, a straight-cut shirt hangs from the hips, not the shoulders — check both values honestly.
-
03
T-shirt length
Measure from the high shoulder point straight down the front to where you want the hem to end. A classic length finishes at mid-hip, roughly 65–72 cm for average heights; cropped styles stop at or above the waist. The generator adds the hem allowance separately below the dashed line, so this is the finished visible length.
-
04
Shoulder width
From the high shoulder point to the shoulder bone at the top of the arm — find the bone by raising and lowering your arm and feeling the joint move. Typical values are 11–13 cm. For a regular fit the sleeve seam sits on this bone; a relaxed or oversized preset deliberately extends past it, but that drop is added by the draft, not by your measurement.
-
05
Armhole depth
From the high shoulder point vertically down to the level of the underarm crease. Clamp a ruler or a book horizontally under the arm and measure down the front to its upper edge — typically 18–22 cm. This value sizes the armhole the sleeve cap has to match: too shallow cuts into the underarm, too deep restricts arm lift because the whole side of the shirt moves with the arm.
-
06
Bicep
Measure around the fullest part of the upper arm with the arm relaxed and hanging down; a flexed arm adds 2–3 cm you do not wear all day. The sleeve width comes from this value plus ease, and on short knit sleeves a snug bicep is the most common complaint — when in doubt round up, never down.
-
07
Sleeve length
From the shoulder bone down the outside of the arm to the desired sleeve end — a classic short sleeve finishes 20–26 cm from the shoulder point, roughly mid-bicep. Long sleeves run to the wrist bone with the arm slightly bent. Remember the generator measures from the shoulder point, not from the neck.
Typical ranges and knit ease
The body columns are orientation values for sanity-checking. The ease column is the more useful one: unlike wovens, a knit T-shirt is often drafted with very little positive ease, and fitted styles use zero or negative ease — a finished chest smaller than the body — because the fabric stretches to cover the difference.
| Reference size | Chest/bust (cm) | Hips (cm) | Typical knit chest ease (cm) |
|---|---|---|---|
| EU 36 / S | 82–86 | 90–94 | 0 to +4 |
| EU 38 / S–M | 86–90 | 94–98 | 0 to +4 |
| EU 40 / M | 90–94 | 98–102 | 0 to +5 |
| EU 42 / L | 94–99 | 102–106 | 0 to +5 |
| EU 44 / L–XL | 99–104 | 106–111 | +2 to +6 |
| EU 46 / XL | 104–110 | 111–116 | +2 to +6 |
Read the ease column against your fabric: a stable interlock with 20% stretch wants ease at the top of the range, a stretchy jersey with 50% stretch tolerates 0 or even −2 to −4 cm for a body-hugging fit. An oversized look is +10 cm and more — at that point stretch barely matters and the shirt behaves almost like a woven.
Common measuring mistakes
Trusting the size label instead of the tape
Ready-to-wear T-shirt sizes vary by 8–10 cm between brands for the same letter. Entering measurements copied from a size chart you usually buy defeats the point of a generated pattern — measure the body, then adjust ease for the look you want.
Measuring the chest with lifted arms
Raising the arms to hold the tape expands the ribcage and shifts the tape upward, adding 2–4 cm. Wrap the tape, then lower both arms and relax before reading the value in a mirror.
Measuring a flexed bicep
The bicep should be measured relaxed and hanging. A flexed reading produces a sleeve that flaps; more common is the opposite habit of measuring loosely and getting a sleeve that grips — the tape should touch the skin all around without denting it.
Copying shoulder width from a dropped-shoulder shirt
Measuring shoulder-seam to shoulder-seam on a relaxed shirt you like gives 45–50 cm across the back — but the generator asks for your single body shoulder, neck to bone, around 11–13 cm. Enter the body value and get the relaxed silhouette from the preset instead.
Ignoring the fabric when choosing ease
Ease chosen for 'a knit' in general fails: the same +2 cm that is comfortable in stretchy jersey feels tight in stable interlock. Do the stretch test on the actual fabric first, then set chest and hem ease — the draft cannot know your fabric.
Adding seam allowance to measurements
The generator adds the seam and hem allowances you select as a separate dashed cutting line around each piece. Padding your body values 'for the seams' double-counts them and produces a shirt a full size too big.
From measurements to a T-shirt that fits
Test the stretch percentage before choosing ease
Fold your fabric 10 cm from a crossgrain edge, mark a 10 cm section of the fold, and stretch it along a ruler until it resists comfortably — not to its absolute limit. If 10 cm reaches 13 cm, the fabric has 30% stretch; 15 cm means 50%. Under 25% is a low-stretch knit that behaves half-woven and needs positive ease; 30–50% covers most jerseys; over 50% with lycra allows real negative ease.
Choosing ease, including zero and negative
As a working rule for chest ease: low-stretch knits +4 to +6 cm, average jersey 0 to +4 cm for a regular fit, high-stretch fabrics 0 to −4 cm for a fitted shirt. Negative ease only works if the stretch percentage comfortably exceeds the deficit — a shirt 4 cm smaller than a 92 cm chest needs the fabric to stretch about 5% just to lie flat, well within a 30% fabric but hopeless in a 15% one. Hem ease is set separately, so a fitted chest can still have a relaxed hem.
Recovery matters as much as stretch
Stretch is how far the fabric extends; recovery is whether it snaps back. Stretch the 10 cm strip, hold five seconds, release — if it returns to 10 cm quickly, recovery is good; if it stays at 11 cm, the finished shirt will bag at the neckline, cuffs, and seat within a day of wearing. For zero or negative ease, and for any neckband, prioritise fabric with spandex/elastane content, which is what provides recovery.
The neckband is drafted shorter on purpose
The generated neckband is deliberately shorter than the neckline it finishes — it is stretched to fit while sewing, which pulls the neckline curve snug against the body instead of letting it gape. Cut it in rib knit or your main fabric with good recovery, with the greater stretch running along the band's length. If your fabric is unusually stable or stretchy, baste the band first: a gaping band needs shortening, a rippling neckline means the band was too short or overstretched.
Frequently asked questions
Can I use this pattern with a woven fabric?
Not directly. The draft is calculated for knits: the ease is far smaller than a woven needs, the neckline is finished with a stretched band instead of a facing, and there are no darts or shaping seams. In a non-stretch poplin the same pattern would be tight across the chest and impossible to pull over the head. For wovens, use a block drafted for them.
How do I know how much my fabric stretches?
Fold the fabric and mark 10 cm along the fold across the grain (selvedge to selvedge direction). Hold the left mark at zero on a ruler and stretch the right mark until the fabric resists comfortably. Reaching 13 cm means 30% stretch, 14 cm means 40%, and so on. Test the lengthwise direction too — many jerseys stretch much less along the grain, which affects sleeve and body length behaviour.
What does negative ease mean and when should I use it?
Negative ease means the finished garment measures less than your body — for example a 88 cm chest on a 92 cm body is −4 cm ease — and the knit stretches to cover the difference. Use it only for fitted styles in fabric with at least 30% stretch and good recovery. For a first shirt from the generator, 0 to +4 cm at the chest is the safer starting point.
Why doesn't the sleeve cap have gathering ease like other patterns?
Woven sleeve caps carry 2–4 cm of extra length that is eased in to shape the shoulder. Knit sleeves are drafted nearly flat: the generator builds the cap toward the measured front and back armhole lengths and checks the resulting difference before export, because knits ease only minimally and any real surplus would show as puckers. That flat cap is also why knit sleeves can be sewn in before closing the side seams.
How should I print and verify the pattern?
Export A4 tiled PDF for home printing, copyshop PDF for a single full-size sheet, or SVG for vector editing. Print at 100% with any fit-to-page scaling disabled, then measure the 5 × 5 cm test square printed on the sheet before trimming — if it is off by even a millimetre per side, that error multiplies across a 50 cm pattern width. Remember the dashed line is the cutting line with allowances; the solid line is the sewing line.