How To · Fashion · Alterations
Measure Yourself for Perfect Alterations
A tailor is only as good as your measurements. Here's how to capture the dimensions that matter—and avoid the guesswork that leads to expensive mistakes.
5 min read · IrisAlterations are the secret weapon of people who actually look polished. But they only work if your tailor has the right numbers. A quarter-inch difference in a shoulder seam or inseam can be the difference between 'almost fits' and 'this was made for me.'
The good news: you don't need a professional seamstress to measure yourself. You need a flexible measuring tape, a mirror (or a friend), and five minutes of focus. Here's exactly how to do it.
A quarter-inch difference in a shoulder seam can be the difference between 'almost fits' and 'this was made for me.'
What you'll need.
- 01Flexible measuring tape (fabric, not rigid)
- 02Full-length mirror
- 03Fitted undergarments (bra, shapewear if applicable)
- 04Shoes you'll wear with the garment
- 05Pen and paper or notes app
Step one · 1 minute
Gather your tools and dress appropriately
You'll need a flexible measuring tape (the soft fabric kind, not a rigid ruler). Wear a fitted tank top or bra and the type of undergarments you'd wear with the garment being altered. Stand barefoot or in the shoes you plan to wear with the piece. Good lighting and a full-length mirror are essential. If you're measuring a friend or having someone measure you, that person should be at eye level with the measurement point.
Keep the measuring tape parallel to the ground at all times. Tilting it creates false measurements.
Step two · 1 minute
Measure your bust
Wrap the tape measure snugly around the fullest part of your chest, keeping it horizontal and parallel to the ground. Don't pull tight—the tape should sit comfortably against your skin with just enough give to fit one finger underneath. Record this number. This measurement is critical for jacket and dress alterations, especially at the side seams.
Measure while wearing the exact bra you'd pair with the garment. Different bras create different silhouettes.
Step three · 2 minutes
Measure waist, hips, and inseam
For your waist: measure at the narrowest point, typically about an inch above your navel. Keep the tape relaxed. For your hips: measure around the fullest part of your hip and buttocks, usually 7–9 inches below your waist. For inseam: stand in the shoes you'll wear with the pants. Measure from your inner thigh (where the inseam naturally sits) down to the top of your shoe heel. This is the measurement tailors use most frequently for hemming.
Have someone else measure your inseam if possible—it's genuinely difficult to get accurate on yourself. If you're solo, use a mirror and go slowly.
Step four · 1 minute
Capture shoulder and sleeve length
For shoulder width: measure from the outer edge of one shoulder bone to the outer edge of the other, across the back. Keep the tape straight and level. For sleeve length: bend your arm slightly at the elbow and measure from the center back neck, across your shoulder, down your arm to your wrist bone. This is how tailors determine where the sleeve should end on you specifically.
Shoulder measurements are less forgiving than you'd think. Even a half-inch off will be visibly wrong. Measure twice.
Step five · 2 minutes
Document and communicate with your tailor
Write down all measurements in inches (or centimeters, depending on your tailor's preference). Include the garment type, color, and any specific alterations you want—hemming, taking in at the side seams, tapering sleeves, etc. Take a photo of the garment if possible. When you meet with your tailor, show them the measurements and try the garment on in front of them. They may adjust based on how the fabric drapes on your body.
Bring the shoes or undergarments you measured in. Your tailor may want to see how they affect the fit.
Step six · 1 minute
Verify the fit before final alterations
Most tailors will do a fitting after initial alterations. Try the garment on in the same undergarments and shoes you measured in. Check that seams sit where they should, that hems are level, and that the overall silhouette feels right. Don't settle for 'close enough.' A good tailor expects feedback and will make adjustments. This is your last chance to catch issues before the work is finalized.
Move around in the garment. Sit, raise your arms, walk. Alterations that look good standing still might pull when you move.
How to know your measurements are accurate
Your tailor should confirm your measurements make sense for your frame and the garment type. When the altered piece comes back, it should feel like it was made for you—no pulling, no excess fabric, and seams that land where they naturally should on your body.
Questions at the mirror.
What if I'm between sizes and don't know which measurements to use?
Measure yourself as you are right now. Don't anticipate weight loss or gain. If you're genuinely between sizes, bring the garment to your tailor and let them assess which size is more workable. Sometimes the smaller size can be let out; sometimes the larger needs taking in. Your tailor will advise based on seam allowances.
Can I measure myself while wearing the garment I'm altering?
No. Measure your body, not the garment. The garment may already fit poorly, which is why you're altering it. Your body measurements are the baseline your tailor needs.
How often should I re-measure if my body changes?
If your weight or body composition shifts noticeably, take new measurements before ordering alterations. Bodies change, and your old measurements may no longer be accurate. It's worth the ten minutes to get it right.
Should I give my tailor measurements or just try things on?
Do both. Written measurements give your tailor a starting point, especially if you can't visit in person. But an in-person fitting is always better because your tailor can assess how fabric drapes on your specific frame and posture.