Jun 2, 2026

What Size Suit Am I? How to Measure Yourself at Home (2026 Guide)

Quick answer: Your suit size is your chest measurement in inches plus a length letter — Short (S), Regular (R), or Long (L). If your chest measures 40 inches and you're average height, you wear a 40R. Measure your chest around the fullest part, then pick the length letter based on your height. That's the whole formula — the rest of this guide shows you exactly how to take each measurement at home and read a size chart with confidence.

What does a suit size like "40R" actually mean?

A men's suit size has two parts: a number and a letter.

The number is your chest size in inches. A 40 jacket is built for roughly a 40-inch chest. Sizes step up in even numbers: 36, 38, 40, 42, and so on.
The letter is the jacket length, based on your height. S = Short, R = Regular, L = Long. The letter controls how far the jacket falls and how long the sleeves are — not how wide it is.

So a 42L fits a 42-inch chest on a taller frame, while a 38S fits a 38-inch chest on a shorter one. Two men with the same chest can wear different sizes purely because of height.

How to measure yourself for a suit (step by step)

You only need a soft cloth tape measure, a fitted shirt, and ideally a friend to help — back and shoulder measurements are hard to take accurately on yourself. Stand naturally, breathe normally, and keep the tape snug but not tight.

Diagram showing how to measure a man for a suit: shoulder, chest, waist, sleeve, and jacket length

1. Chest (this sets your jacket number)

Wrap the tape around the fullest part of your chest, just under your armpits and across your shoulder blades. Keep it level all the way around and leave room for one finger underneath. The number you get is your jacket size. If you land between sizes, round up.

2. Waist

Measure around your natural waistline — roughly where your belt sits, near the navel — not where low-rise jeans ride. This sets your trouser size and helps confirm the jacket's shape.

3. Shoulders

Measure straight across the back from the edge of one shoulder seam to the other. Shoulders are the one area that's difficult to alter afterward, so getting this right matters most.

4. Sleeve

Measure from the top of the shoulder down to your wrist bone, with your arm relaxed at your side. Sleeves can usually be shortened or lengthened by a tailor, so treat this as a starting point.

5. Jacket length

From the base of your collar to where you want the jacket to end — a good rule is around the middle of your cupped hand. This, together with your height, tells you whether you're an S, R, or L.

6. Inseam (for the trousers)

Measure from the crotch to the bottom of the ankle, or simply measure a pair of trousers you already love along the inside seam. Hems are an easy tailoring fix.

How do I know if I'm Short, Regular, or Long?

Use your height as the guide:

Short (S): up to about 5'7"
Regular (R): about 5'8" to 6'0"
Long (L): 6'1" and taller

If you're right on the border, your torso length matters more than your total height — longer-legged men can sometimes size to Regular even when they're tall, and vice versa.

Men's suit size chart

This chart is a guide. Sizing varies slightly between brands and between classic, modern, and slim fits, which is why a quick in-person check is always worth it.

What is "drop" and why does it matter?

Drop is the difference between the jacket chest and the trouser waist that comes with a suit. The standard drop is 6 — a 40 jacket pairs with a 34 trouser (40 minus 6). Athletic and slim cuts often use a drop 7 for a more tapered look. If your waist is much larger or smaller than the standard drop, you'll likely buy the jacket and trousers as separates, or have the trousers tailored.

5 common mistakes when measuring at home

Pulling the tape too tight. It compresses the measurement and gives you a jacket that won't close comfortably.
Measuring over a bulky sweater or jacket. Always measure over a thin, fitted shirt.
Letting the tape sag in the back. Keep it level all the way around, especially across the shoulder blades.
Confusing chest size with shirt size. Your suit number is your chest in inches, not your neck or shirt collar size.
Skipping the length letter. The right number in the wrong length is still the wrong suit.

Why an in-person fitting still wins

At-home measurements get you 90% of the way there — perfect for narrowing down a size before you shop. But fabric, cut, and posture all change how a suit actually sits on your body, and the shoulders and chest are the hardest areas to judge from a tape alone. A two-minute fitting catches what a tape can't.

At Hollywood Suits, we've been fitting men since 1985, and you can walk in for a measurement and same-day suit at any of our three Southern California stores — Hollywood, Westminster (Orange County), and Torrance (South Bay). Bring your at-home numbers, and one of our sales representatives will measure you and confirm your exact size. For alterations, there is a trusted tailor right next door. Browse our suit collection to see what's in stock before you visit.

Frequently asked questions

Is suit size the same as chest size?

Yes — the number in your suit size is your chest measurement in inches. A 42 jacket is made for about a 42-inch chest. The letter after it (S, R, or L) refers to length, not width.

What size suit am I if I'm 5'10" and 175 pounds?

Most men of that height and weight land around a 40R, but it depends on your chest measurement and build. Measure your chest to confirm the number, and use Regular length since 5'10" falls in the Regular range.

What does 40R mean on a suit?

40R means a 40-inch chest in a Regular length. It's one of the most common men's suit sizes and fits an average-height man with a 40-inch chest.

Should I size up if I have an athletic or muscular build?

Buy the jacket for your chest measurement, not a size up. If your chest is much larger than your waist, look for an athletic or slim cut with a drop 7, or buy your jacket and trousers as separates so each piece fits.

Can I figure out my size from a suit I already own?

Yes. Lay a well-fitting jacket flat and measure across the chest from armpit seam to armpit seam, then double it — that's close to your jacket number. Check the inside label too; most suits list the size there.