How to Hem Active Pants for Perfect Fit?

Active pants that are too long can bunch at your ankles, trip you during workouts, or just look sloppy. Whether you've bought new Lululemon-inspired leggings or your favorite gym pants have stretched out of shape, hemming them yourself saves money and ensures a perfect fit tailored to your height and activity level.

In this guide, you'll learn a simple, intermediate sewing method using a machine for durable results on stretch fabrics. We'll cover measuring accurately, pinning for stretch, and sewing a clean blind hem that maintains flexibility. Expect crisp, even legs that move with you.

The process takes 30-45 minutes per pair, perfect for intermediate sewers comfortable with basic machine operation. No advanced skills required, but patience with stretchy material is key.

▸What You'll Need

• •Measuring tape or ruler
• •Fabric marking chalk or washable pen (required for stretch fabrics)
• •Straight pins (required)
• •Sewing machine with stretch or ballpoint needle (required; size 70/10 or 80/12)
• •Matching polyester or stretch thread (required)
• •Iron and ironing board
• •Sharp fabric scissors or rotary cutter
• •Hem gauge or ruler (optional but recommended)
• •Seam ripper (optional for adjustments)

Estimated Time: 30-45 minutes per pair Difficulty: intermediate

▸Step-by-Step Instructions

Step 1: Prepare Your Workspace and Pants

Clear a flat, well-lit surface like a table. Turn your active pants inside out to protect the outer fabric and expose seams. Wash and dry them first to pre-shrink any fabric movement—activewear often has spandex that settles after laundering.

Lay pants flat and inspect the current hem. Note the fabric type (e.g., nylon-spandex blend). Success here: Pants are clean, inside out, and ready without twists.

Why it matters: Prevents shrinkage surprises and makes marking easier.

💡 Tips:

• •Work in natural light for accurate measurements.
• •Use a mannequin or chair back to mimic body shape.

⚠️ Warnings:

• •Avoid ironing dirty pants to prevent setting stains.

Step 2: Try On and Measure Desired Length

Wear shoes or socks you use for activity. Stand straight or in your workout stance, have a helper mark where the pant leg should end—typically 1/4-1/2 inch above the floor to avoid dragging.

Measure from crotch seam down both legs to the mark. Compare sides for evenness. Success: Consistent measurement on both legs, e.g., 28 inches.

Why it matters: Ensures symmetry and prevents tripping.

💡 Tips:

• •Add 1-1.5 inches extra for hem allowance.
• •Measure while pants are on for true fit.

⚠️ Warnings:

• •Don't guess—measure precisely to avoid uneven legs.

Step 3: Mark the New Hem Line

Lay pants flat, align legs. From the bottom raw edge, measure up your desired hem allowance (1 inch standard for active pants) plus fold depth (another 1 inch). Mark with chalk around the entire leg at this level.

Repeat for inseam to ensure straight line. Connect marks lightly. Success: Clear, even chalk circle 2 inches above original hem.

Why it matters: Guides precise folding for professional look.

💡 Tips:

• •Use a hem gauge for consistency.
• •Mark inside for no-show lines.

Step 4: Fold and Pin the Hem

Fold the fabric up to the marked line, wrong sides together for a clean double fold. Press lightly with iron to set crease, then fold again enclosing raw edge. Pin every 2-3 inches, easing in stretch to avoid puckers.

Success: Smooth, pinned fold that lays flat without pulling. Test stretch by tugging gently.

Why it matters: Double fold prevents fraying on activewear.

💡 Tips:

• •Pin perpendicular to fold for easy removal while sewing.
• •Steam iron helps set stretch without scorching.

⚠️ Warnings:

• •Over-pin can distort stretch—space pins adequately.

Step 5: Iron the Fold Securely

Press the pinned hem with medium heat (synthetic setting for active fabrics). Use a pressing cloth to protect spandex. Roll the fold over ironing board edge for sharpness.

Remove pins after cooling. Success: Crisp, permanent crease ready for sewing.

Why it matters: Heat sets the fold, making sewing straight easier.

💡 Tips:

• •Hover iron for delicate fabrics.
• •Quick steam burst relaxes fibers.

Step 6: Sew the Blind Hem

Install stretch needle and thread machine with matching polyester thread. Set to zigzag or blind hem stitch (width 2-3mm for flex). Sew 1/8 inch from fold edge, catching just fabric sparingly.

Go slow, stretch fabric slightly ahead of needle. Backstitch at ends. Success: Invisible stitches from outside, secure inside.

Why it matters: Blind hem preserves stretch and look.

💡 Tips:

• •Test stitch on scrap first.
• •Use walking foot attachment for even feed.

⚠️ Warnings:

• •Wrong needle causes skipped stitches or breaks.

Step 7: Trim Excess and Finish

Turn right side out. Trim any excess inside fabric close to seam (1/4 inch). Zigzag raw edges if needed for durability. Press final hem.

Success: Clean, even hem that stretches fully.

Try on: Legs hit perfectly without drag.

💡 Tips:

• •Grade seams for bulk reduction.
• •Topstitch lightly outside for reinforcement.

▸Pro Tips

• •Pre-wash twice to account for maximum shrinkage.
• •Cut hem tape for no-sew option on super-stretchy pants.
• •Measure both legs separately—bodies aren't symmetric.
• •Use LED sewing light for precision on dark fabrics.
• •Freeze pants before hemming to stiffen for easier handling.
• •Practice on old pants to dial in your machine tension.
• •Hem while slightly damp for better crease hold.

▸Common Mistakes to Avoid

• •Not accounting for stretch: Causes puckers—always ease fabric.
• •Uneven measuring: Leads to crooked legs—double-check marks.
• •Wrong needle/thread: Skips or breaks—use ballpoint and polyester.
• •Insufficient allowance: Hem too tight, loses flex—add extra inch.
• •Ironing too hot: Melts spandex—use low heat always.

▸Troubleshooting

Problem: Hem puckers or waves

Solution: Reduce tension, stretch fabric while sewing. Repin looser.

Problem: Stitches show on outside

Solution: Adjust blind hem guide closer to fold. Re-sew with finer stitch.

Problem: Uneven length after wash

Solution: Over-hem by 1/4 inch initially. Re-wash test post-sewing.

Problem: Machine skips stitches

Solution: Swap to fresh stretch needle. Clean bobbin case.

Problem: Fabric won't fold flat

Solution: Steam heavily and use clips instead of pins. Seek pro for heavy elastane.

Schmetz Stretch Twin Needle Size 75/11

Perfect for activewear's spandex—prevents skipped stitches and adds professional finish.

Best for: Sewing the blind hem on stretch fabrics.

Price Range: $4.99-$6.99

Dritz Ezy-Hem Gauge

Adjustable tool ensures precise, even folds every time—essential for symmetry.

Best for: Measuring and pressing hem allowance accurately.

Price Range: $4.99

Fiskars 8-Inch Fabric Scissors

Sharp, glide-cut blades handle stretch without fraying edges cleanly.

Best for: Trimming excess fabric post-sewing.

Price Range: $15-$20

Gutermann Mara 70 Polyester Thread

High-stretch thread matches activewear durability and colorfastness.

Best for: Matching thread for invisible seams.

Price Range: $3.99-$5.99

Clover Fabric Marker Chaco Pen

Washable chalk marks vanish after sewing—safe for synthetics.

Best for: Precise leg marking without residue.

Price Range: $8.99-$12.99