How to measure clothing for a tech pack (flat garment method)
Step by step: how to measure a garment lying flat, where to place the tape for chest, length, shoulder and sleeve, and how to turn the numbers into a spec sheet.
Updated 1 October 2026 · By Hem Apparel
The easiest way to start a spec sheet is to measure a garment that already fits the way you want. The garment measurement method is the one factories use: lay the piece flat and measure straight lines between fixed points.
Before you start
- Use a soft tape measure marked in centimetres.
- Wash and dry the garment first, so you measure the size customers will wear.
- Lay it on a flat table, smooth out wrinkles but do not stretch it.
- Button or zip it closed, and fold any open sides flat.
- Record whether each number is flat half-width or full circumference.
Where to measure
| Point | How to measure |
|---|---|
| Chest width | Straight across, 2.5 cm below the armhole seam, from side seam to side seam |
| Body length | From the highest point of the shoulder next to the neck, straight down to the hem |
| Shoulder width | Across the back from one shoulder seam end to the other |
| Sleeve length | From the shoulder seam end along the top of the sleeve to the cuff or hem edge |
| Neck width | Across the neck opening from seam to seam at the widest point |
| Neck drop | From the high shoulder point to the front neck seam, measured straight down |
| Hem width | Straight across the bottom edge, relaxed |
| Sleeve opening | Across the end of the sleeve, relaxed |
Flat measurements and circumference
Flat measurements are half the circumference. A chest that is 56 cm flat is 112 cm around. Pick one convention and write it in the spec header. Mixing the two is the most common reason a pattern comes out the wrong size.
Measuring ribs and stretch fabric
Measure ribs relaxed and, if the stretch matters, also note a stretched measurement. For example, a neck rib of 18 cm relaxed that stretches to 28 cm. Write both so the factory can match the recovery.
Turn the numbers into a spec sheet
- Record each measurement as your base size.
- Add a grade for every other size.
- Add a tolerance to each row.
- Write a short how-to-measure note for every point, so anyone can check it.
- Send the garment itself with your first sample request if you can.