Measuring Tools

Accurate measuring sits underneath everything in dressmaking: choosing a size, adjusting a pattern, laying pieces on grain, drafting, and checking hems. A handful of tools covers it, and only the first three are needed to start.

The essentials

Tape measure. A flexible tape, usually 60" (150 cm) long, for body measurements, curved pattern edges, and checking fabric lengths. Choose a fibreglass tape, which doesn't stretch, and one printed on both sides, ideally with inches on one side and centimetres on the other. Cloth tapes stretch over time and can be out by an inch or more, so check an old tape against a metal ruler and replace it if it's drifted. A tape with a metal tip at each end is easier to hold at one point.

Clear gridded ruler. A transparent acrylic ruler printed with a grid (in 1/8" or 5 mm steps), commonly 2" × 18" (5 × 45 cm). Being able to see the fabric or pattern through it is the point. Use it to add or check seam allowances, draw lines parallel to an edge, mark buttonhole positions, cut bias strips at 45 degrees (most have angle lines), and check right angles. It's the most-used tool in pattern alteration.

Seam gauge. A small 6" (15 cm) ruler with a sliding marker. Set the slider once, then use it to measure hem depths, seam allowances, pleat depths and buttonhole spacing repeatedly without re-reading the scale.

For pattern work and drafting

French curve. A flat template with tight, changing curves, used to draw and true armholes, necklines, crotch curves and collar edges. Slide it along until a section of its edge matches the curve you need, connecting your guide points.

Hip curve. A long, gently curved ruler, about 24" (60 cm), for the long shallow curves of side seams, hiplines, hems and trouser legs, which are too gradual for a French curve.

Pattern master or design ruler. A combined tool (an L-square with curves) used by professional patternmakers. It does the work of several rulers at once.

L-square (tailor's square). A large right-angled ruler for drawing perpendicular lines, squaring grainlines and hems, and drafting blocks.

Yardstick or metre stick. For long straight lines, marking hems from the floor, and checking grain over long distances.

Flexible curve. A bendable ruler that holds whatever shape you give it. It's useful for copying a curve from an existing garment, or measuring the length of a curved seam on a pattern.

For fitting and hemming

Hem marker. A stand with a ruler and a chalk puffer or pin clamp that marks a hem at an even height from the floor while the wearer turns slowly. It's the most reliable way to level a skirt hem, especially on bias-cut and circle skirts. A yardstick and a helper with pins does the same job.

Narrow elastic. Not strictly a measuring tool, but a length tied around the waist marks the natural waistline, so every vertical measurement uses the same reference.

Measuring well

The tool matters less than how it's used. Most measuring errors come from technique:

• Measure the body snug but not tight. The tape should lie flat against the body without pressing in. Measure each body measurement twice, and take a third reading if the two differ.
• Keep horizontal measurements level all the way around. Check in a mirror or have a helper.
• Measure flat pattern pieces between the seamlines, not the cutting lines, and exclude darts and pleats, when comparing a pattern's size with your body.
• Stand curved pattern edges on edge. To measure a curved seam, such as an armhole, stand the tape on its edge and walk it around the curve.
• Stick to one system. Mixing inches and centimetres in one project invites errors. If a pattern is metric, measure in metric.

The Body Measurement Worksheet explains where to take each body measurement and keeps a printable record. The Seam Allowance Converter converts between inches and millimetres.

A starter set

If you're buying tools for the first time: a fibreglass tape measure, a clear gridded ruler, and a seam gauge. Add a French curve and a hip curve when you start altering patterns, and an L-square when you start drafting.