How to Measure for a Custom Prom Dress: A Step-by-Step Fit Guide

Finding the perfect prom dress should be exciting, not stressful. At 27dress, we know that a dress made to your exact measurements will fit better and feel more like you than anything off the rack. This step-by-step guide will show you exactly how to measure for a custom prom dress at home, so you can order with total confidence.

What You’ll Need Before You Start Measuring

Before you pick up a tape measure, set yourself up for success. Accurate measurements are the foundation of a great fit, so a little preparation goes a long way. You’ll need a soft fabric measuring tape (not a metal one from a toolbox), a full-length mirror, and something to write down your numbers. Wear the undergarments you plan to wear with your dress—whether that’s a strapless bra, shapewear, or seamless underwear—since these can change your natural silhouette by an inch or more.

Stand naturally with your feet together and arms relaxed at your sides. Do not suck in your stomach, pull the tape too tight, or add extra “wiggle room.” We’ll handle the ease and fit allowances on our end. For the most consistent results, ask a friend to help you measure, especially for back and shoulder areas. Write down every number immediately so you don’t forget.

Step 1: The Three Essential Body Measurements

For a custom prom dress, you only need three core measurements to start: bust, waist, and hips. These are the same measurements we use to match you to our size chart for US sizes 0–30 or to build a fully custom pattern from scratch. Here is how to take each one correctly.

• Bust: Wrap the tape around the fullest part of your chest, usually across the nipple line. Keep the tape parallel to the floor and snug but not tight enough to compress your bust. Let your arms hang naturally; do not raise them.
• Waist: Find your natural waist—the smallest part of your torso, typically about an inch above your belly button. Bend to one side; the crease that forms is your natural waist. Measure around this point, keeping one finger between the tape and your skin for a comfortable fit.
• Hips: Stand with your feet together and measure around the widest part of your hips and seat. This is usually 7–9 inches below your natural waist. Make sure the tape passes over the fullest part of your bottom and doesn’t dip in the back.

Double-check each measurement by taking it twice. If the numbers differ by more than ¼ inch, measure a third time and use the average. Record these as your baseline for any 27dress order.

Step 2: Additional Measurements for a Custom Fit (Especially for Curvy or Petite Frames)

While bust, waist, and hips cover most standard sizes, a truly custom prom dress may require a few extra details. If you are between sizes, have a shorter or longer torso, or want a specific silhouette like a mermaid or fit-and-flare, these measurements ensure the dress follows your unique shape.

• Shoulder to Waist (Front): Measure from the center of your shoulder (where a seam would sit) down over your bust to your natural waist. This helps us place the waistline at the right height for your torso.
• Waist to Floor: Stand straight and measure from your natural waist down to the floor (barefoot). If you plan to wear heels, measure while wearing your intended heel height. This is critical for floor-length gowns.
• Armhole (for sleeved or cap-sleeve styles): With your arm slightly lifted, measure around the top of your shoulder joint where your arm meets your body. Keep the tape snug but comfortable.
• Upper Arm (for fitted sleeves): Measure around the fullest part of your upper arm, about halfway between your shoulder and elbow. Relax your arm completely.

If you have a larger bust, a shorter waist, or carry most of your weight in your hips, providing these extra numbers helps us adjust the dress without extra bulk or gaping. When in doubt, more data is always better.

Step 3: How to Measure for Specific Prom Dress Silhouettes

Different dress styles fit differently, and a few targeted measurements can make or break the final look. Here is how to adjust your approach for the most popular prom silhouettes.

• A-Line or Ball Gown: Focus on your natural waist and bust measurements. The skirt will flare from the waist, so the hip measurement is less critical, but still helpful. Add your waist-to-floor length to ensure the hem hits right.
• Mermaid or Trumpet: In addition to bust, waist, and hips, measure your hip depth (from your natural waist down to the fullest part of your hip) and your knee circumference. This ensures the fitted portion ends at the right spot and the flare doesn’t start too high or low.
• Sheath or Bodycon: These require the most precision. Measure your torso length (from shoulder to crotch, front and back) and your shoulder width (from bone to bone). A snug but not tight fit is the goal.
• High-Low or Asymmetrical: Measure both the front and back waist-to-floor lengths separately. Even a slight difference in hem height can look intentional or accidental, so be exact.

If you are ordering a style with a deep V-neck or open back, also measure from your collarbone to your natural waist (front)

Explore made-to-order styles in our prom collection, or read our complete guide for more on fit, fabric and styling.