Start with measurements and a basic block

The fastest way to make shorts is to start with a basic block — a straightforward, well-fitting pattern piece that you adjust rather than draft from scratch. A block gives you the waist, hip, inseam, and rise measurements you need without having to calculate angles and curves. You can buy a commercial block (Simplicity and McCall's sell them), trace one from an existing pair of shorts that fit well, or read a free one from sites like Craftsy or Threads Magazine.

Measure yourself or the person who will wear the shorts. You need: waist (around the narrowest part), hip (around the fullest part, usually 8 to 9 inches below the waist), inseam (from the inside of the ankle to the crotch while standing), and rise (from the waist down to where the crotch seam will sit). Write these down. If you are tracing an existing pair, lay them flat on paper, smooth out wrinkles, and trace around the outline with a pencil or marker.

Key Takeaways

  • A basic block — a straightforward foundation pattern — saves you from drafting curves and angles from scratch and can come from a commercial pattern, a pair of shorts that fits, or a free read.
  • Measure waist, hip, inseam, and rise before you start, and write the numbers down so you can adjust the block to your actual size.
  • Add seam allowance (usually half an inch) to every edge of your pattern pieces before you cut fabric, or mark the seam line on the fabric itself.
  • Test your pattern on cheap fabric like muslin or old sheets first; a single fitting can save you from cutting into expensive material.
  • Shorts patterns need a front piece, a back piece, and a waistband strip; the front and back are mirror images of each other.

Adjust the block to your measurements

Once you have a block, compare its measurements to yours. Measure the block's waist opening (the curved edge at the top), hip width (the widest part of the side seam), and inseam length. If the block's waist is 30 inches and yours is 32 inches, you need to add 2 inches total — that is half an inch on each of the four seams (front center, back center, and both side seams).

Mark the adjustment directly on your block with a ruler and pencil. Draw a new line parallel to the original seam line, moving it outward by the amount you need. Do the same for the hip and inseam. If the inseam is too long, you can shorten it by marking a new hemline lower on the pattern. If it is too short, you may need a different block or a pattern designed for a longer rise.

Once you have adjusted the block, trace the new outline onto fresh pattern paper. This becomes your working pattern — the one you will use to cut fabric. Keep the original block in case you need to make a different size later.

Add seam allowance and mark grain lines

Seam allowance is the space between the edge of the fabric and the line where you actually sew. Most garments use half an inch. If your block does not already include seam allowance, draw a line half an inch away from every edge — the waist, the inseam, the outseam (the outer leg seam), and the leg opening. This expanded outline is what you will cut from fabric.

Mark the grain line on your pattern pieces with an arrow pointing up. The grain line shows which direction the fabric's threads run, and it should run parallel to the center front and center back of the shorts. Grain line matters because fabric stretches differently along the grain than across it; cutting against the grain can make your shorts baggy or twisted.

Label each piece clearly: "Front" and "Back," with arrows showing which way is up. Write your measurements on the pattern so you remember what size it is. If you are making shorts for someone else, write their name and the date.

Create a muslin test garment

Before you cut into the fabric you actually want to wear, cut a test version from muslin — a cheap, plain cotton fabric sold at any fabric store. Muslin lets you check the fit without wasting expensive material. Cut out the front and back pieces, add a straightforward waistband (a strip of muslin 2 inches wide and as long as your waist measurement plus seam allowance), and sew it together with a basic running stitch or a sewing machine.

Put on the muslin shorts and check the fit. Does the waist sit where you want it? Are the legs the right length? Is there enough room in the hip and thigh, or do they pull? Mark any changes with a pen or chalk while wearing them. If the waist is too loose, pinch the excess and mark how much to take in. If the inseam is too long, fold the hem up to the right length and mark it.

Take off the shorts and transfer your marks to the pattern. Redraw the seams where you marked changes, then make a second muslin version to confirm the fit. This step takes an hour but saves you from cutting a mistake into fabric that costs three times as much.

Prepare your final pattern for cutting

Once your muslin fits well, transfer all your changes back to your paper pattern. Make sure the seam allowance is marked clearly — some sewers draw the cutting line in one color and the seam line in another. Pin your pattern pieces to the fabric, making sure the grain line arrow points in the same direction on every piece.

If your fabric has a pattern or nap (like corduroy or velvet, where the surface looks different depending on which way you brush it), lay all pattern pieces in the same direction. This uses more fabric but prevents the shorts from looking like two different colors. For plain fabric, you can flip the back piece to save material.

Cut slowly and carefully along the cutting line. Use sharp scissors or a rotary cutter and ruler. Mark the seam line on the fabric with tailor's chalk or a fabric pencil if you prefer to sew along a marked line rather than eyeballing the seam allowance.

Add closures and finishing details to your pattern

Your basic pattern covers the leg and hip, but shorts also need a waistband and a way to open and close. The simplest option is a drawstring waistband — a casing (a tunnel of fabric) at the waist with a cord threaded through it. To add this to your pattern, extend the waist seam allowance upward by 1.5 to 2 inches. This extra fabric becomes the casing when you fold it down and sew it in place.

If you want a button or zipper fly, you will need to add a fly shield — an extra piece of fabric that covers the opening. This is more complex and usually comes with a commercial pattern rather than a basic block. For your first pair, a drawstring or elastic waistband is faster and more forgiving.

Mark the leg opening width on your pattern. Most shorts have a leg opening of 8 to 12 inches around, depending on how loose you want them. If your block's leg opening is too wide or too narrow, adjust it the same way you adjusted the waist — by moving the seam line inward or outward.

Frequently Asked Questions

Do I need to buy a commercial pattern or can I make one from scratch?

You can make one from scratch, but it takes longer because you have to draft curves for the crotch and hip. Starting with a basic block or tracing an existing pair of shorts saves hours. If you want to draft from scratch, look for a book on pattern drafting like "The Practical Guide to Patternmaking for Fashion Design" by Patt and Moulton.

What if I do not have muslin — can I test the fit on regular fabric?

You can, but muslin costs about two dollars a yard and regular fabric often costs five to fifteen dollars. Spending a few dollars on muslin now prevents you from ruining a yard of expensive linen or cotton. Muslin also shows fit problems more clearly because it does not have color or pattern to distract you.

How much fabric do I need to make shorts?

Most shorts need one to one and a half yards of 45-inch-wide fabric, depending on the length and how much you adjust the pattern. Lay your pattern pieces on a piece of paper the size of your fabric and measure the length they take up before you buy. Add a few inches for shrinkage if you plan to wash the fabric first.

Can I use the same pattern to make shorts in different sizes?

Yes, if you keep your original block and adjust it each time. Write the measurements on each adjusted pattern so you know which size it is. Store them in a folder or envelope labeled by size. Over time you will build a set of patterns for different people or different fits.

What is the difference between a pattern and a block?

A block is a basic, straightforward pattern with minimal shaping — it is the foundation. A pattern is a block that has been adjusted for fit, seam allowance added, and details like waistbands and closures included. You make a pattern by starting with a block and customizing it.