How to Make a Sewing Pattern Step by Step: From Body Measurements to Cut Fabric, by Hand or with AI

To make a sewing pattern step by step, you take body measurements, draft a block from those measurements, adapt the block into the design you want to sew and check the fit with a toile before cutting your real fabric. Drafting a sewing pattern can be done entirely by hand, with pattern paper and a pattern ruler, or you can generate a made-to-measure block in software and carry on from there.

Below are the 8 steps in the order a pattern maker works, from tools to cutting. If you want to skip the drafting stage, get a free made-to-measure block and jump straight to step 4.

1. Gather your tools

You don't need much to start, but each tool has a clear job:

• Paper: brown kraft paper or pattern paper on a roll for drafting (sturdy enough for erasing and pinning), plus tissue or tracing paper for copying and transferring lines. The glossary entry on pattern paper explains the types.
• Tape measure of good quality that doesn't stretch.
• Rulers: a long straight pattern ruler (60 cm / 24 in or more), a set square for right angles, and a French curve or tailor's curve for the armhole, neckline, crotch and hip.
• Pencil and eraser, plus a pen in another colour for the final lines.
• Tracing wheel to transfer lines from one sheet to another or onto fabric.
• Paper scissors (never use your fabric shears on paper), tape and pins.
• Toile fabric: calico (muslin in the US) or any cheap fabric of similar weight to your final fabric.

2. Take your measurements

A pattern is only as good as its measurements. Measure over underwear or close-fitting clothes, with the person standing relaxed and looking straight ahead. Before you start, tie a piece of elastic or string around the waist to mark the natural waistline.

Circumferences

• Bust: around the fullest part, with the tape parallel to the floor.
• Waist: at the natural waist, where the string has settled.
• Hip: around the fullest part of the seat, also parallel to the floor.
• Neck, upper arm, wrist, thigh and knee, depending on the garment.

Widths and lengths

• Shoulder: from the base of the neck to the shoulder point.
• Back width and front width: from armhole to armhole, halfway down the armhole.
• Bust height and bust point separation, to place the darts.
• Front and back waist length: from the shoulder to the waist.
• Hip depth: from the waist down to the hip line.
• Crotch depth and outside leg: measure crotch depth with the person seated on a firm chair, from the waist to the seat, and the outside leg down the side, from the waist to where the hem will sit.

Take each measurement twice. If the two don't match, measure a third time and write everything down on a dated sheet. The page on AI pattern making shows how MPattern organises these measurements.

3. Draft the block

The block (or sloper) is the pattern with no design: bodice, skirt, trousers or sleeve with only the minimum wearing ease. It is the one you will reuse for every garment.

By hand

Every drafting system has its own formulas, but a bodice block always starts from the same main lines:

1. A rectangle as wide as half the bust plus ease and as tall as the waist length.
2. The horizontal bust, waist and hip lines, and the armhole depth line.
3. The centre front and centre back lines.
4. The neckline and shoulder line, drawn from the neck point.
5. The armhole, drawn with the French curve between the shoulder point and the armhole depth line.
6. The bust and waist darts, which take up the difference between bust, waist and hip.

Trousers follow the same logic, with waist, hip, crotch, knee and hem lines. Draft in pencil, check that seams that will be sewn together are the same length, and only then go over the lines in pen.

Made-to-measure with AI

The other option is to skip manual drafting. In MPattern you enter up to 38 measurements and the AI drafts a made-to-measure block in your browser: bodice, skirt, trousers, sleeve, dress and more, from a catalogue of 54 base patterns. The result is the same block you would draft by hand, ready for step 4.

If you are weighing up tools, compare them in the guide to the best pattern making software or among the options for free pattern making software.

4. Turn the block into your design

Pattern manipulation turns the block into the design you have in mind. Always copy the block onto fresh paper before you change it, so the original stays intact. The most common changes:

• Darts: pivot the bust dart into the shoulder, armhole, side seam or neckline, or turn it into gathers or a pleat.
• Style lines: replace the dart with a seam, such as a princess line that runs through the bust point.
• Ease: add design ease at the side seams, bust or hip, depending on whether the garment is fitted, straight or loose.
• Lengths and design lines: neckline, hem, waistband, vents, overlaps, pockets and collars.

Check every change: after pivoting a dart or opening a style line, seams that meet must still be the same length.

5. Seam allowance, notches, grainlines and labels

The block and its adaptations are drafted without seam allowance. Before cutting, add:

• Seam allowance: typically 1 cm (3/8 in) on necklines and armholes and 1.5 cm (5/8 in) on side and shoulder seams; at the hem, 3 to 4 cm (1¼ to 1½ in), depending on the finish.
• Notches: small marks showing where pieces meet (waist, armhole, sleeve head, knee). Use one notch on the front and two on the back so the pieces can't be mixed up.
• Grainline: an arrow parallel to the centre of the piece, to be laid parallel to the selvedge.
• Labels: piece name, design, size, how many to cut and whether to cut on the fold.

6. Sew a toile

The toile (muslin) is where you find out whether the pattern works on the body. Cut the pieces from your test fabric, sew them with a long stitch and no finishing, and try it on. Check that:

• the shoulder line and side seam sit in the right place;
• the armhole neither pinches nor gapes;
• the darts point to the right spot;
• on trousers, the crotch neither pulls nor bags;
• the hem falls at the length you want.

Mark adjustments with pins and pen directly on the fabric, transfer the corrections to the paper pattern and, if the change is large, sew a second toile. If you work by draping on a dress form, the logic is the same: the test fabric becomes the pattern, and that is what you check on the body.

7. Cut your fabric

Once the pattern is approved, there are two routes:

• Printed pattern: print the PDF at 100% scale, check the test square with a ruler, tape the sheets together and pin or weight the pattern onto the fabric.
• Projected pattern: with projector sewing patterns, the pattern is projected at 1:1 scale straight onto the fabric, with no printing or taping. You calibrate the scale once and mark or cut along the line.

Either way, follow the grainline, lay the pieces out to use less fabric, and transfer notches and darts with a tracing wheel, tailor's chalk or a fabric marker.

8. Grade sizes, if you need more than one

If the pattern is just for you or one client, you are done. If you plan to sell or produce in several sizes, grading is the last step: enlarging and reducing the pattern proportionally, point by point, for each size in your chart. By hand, this needs a size chart and grading rules for every point on the pattern. The guide to pattern grading explains the process and the digital options.

Where MPattern fits in

MPattern is a web app that runs in your browser, with nothing to install. It covers step 3: the AI drafts a made-to-measure block from up to 38 body measurements. To be clear about what it does not do:

• it does not turn photos or sketches into patterns;
• it does not do 3D simulation;
• it does not adapt your design for you: steps 4 to 6 are still yours.

What is included:

• Free account, no card required, with 3 trial patterns to download as PDF, SVG or DXF.
• One-time payment of €19.99 in the EU or $23.99 elsewhere, which unlocks the app with all 54 base patterns. Optional extra pattern packs cost €2.99 each.
• Projector mode, included in the one-time payment, for cutting with the pattern projected at 1:1.
• Automatic grading on generated patterns, in EU 34–48, UK 6–20, US XS–XXXL and JP 5–19 sizing, with up to 8 nested sizes in one PDF or SVG (the DXF holds one size).
• CAD Editor in the browser, free for importing DXF or SVG, drawing, editing and scaling; exporting from the editor requires MPattern Cloud.
• MPattern Cloud, optional, at €2.99/month, for storing your patterns and files in the cloud.

If you already use professional CAD and are looking at other options, see the pattern making software alternatives.

Summary

A sewing pattern is always made in the same order: tools, measurements, block, design changes, seam allowance and markings, toile, cutting and, if needed, grading. Drafting the block takes the most time, and it is the part you can draft by hand to learn or generate to measure to save time. The toile, on the other hand, is not something to skip: it is what makes sure the pattern fits before you cut your good fabric.