Buying a suit online without trying it on is the part that makes most people nervous. You type in a number, wait for a box, and hope the shoulders do not stick out and the sleeves do not swallow your hands. On Reddit and Quora, the same worries come up constantly: What size suit am I? What do 40R and 42L mean? What if I am between sizes? What can a tailor actually fix?
This guide answers those questions in plain terms. It covers the measurements that matter most, how to turn them into a suit size, how to choose when you fall between sizes, and what to do if the fit is not quite right when your suit arrives.
The Short Answer
Your jacket size is usually close to your chest measurement in inches, and the letter after it reflects your height. A man with a 40 inch chest who is about 5 feet 10 inches tall usually wears a 40R. Your trouser size is based on your waist where suit pants actually sit, which is often different from your jeans size. Always compare your numbers with the size chart for the specific suit you are buying, since sizing varies between brands.
What You Need Before You Measure
- A soft tape measure. A metal tape from the toolbox will give you wrong numbers.
- A friend or family member. You can measure your waist alone, but shoulders and sleeves are much more accurate with help.
- A fitted dress shirt or T shirt and thin pants. Do not measure over a sweater or a jacket.
- Two minutes to stand naturally. Do not hold your breath or pull your stomach in. Measure the body you will be wearing the suit on.
For a step by step walkthrough with diagrams, see our how to measure guide.
The Measurements That Matter Most
- Chest: wrap the tape under your arms and around the fullest part of your chest, keeping it level across your back. This number is the starting point for your jacket size.
- Shoulders: measure across your back from the outer edge of one shoulder bone to the other. This is the hardest part of a jacket to alter, so it matters more than any other number.
- Sleeve: with your arm relaxed at your side, measure from the edge of your shoulder bone down to your wrist bone.
- Waist: measure around where you want your suit trousers to sit, usually at or just below your navel. Keep one finger between the tape and your body.
- Hips: with your feet together, measure around the fullest part of your seat.
- Inseam: measure from the crotch seam down the inside of your leg to where you want the trousers to end. If you have dress pants that fit well, measuring their inseam is often easier and more accurate.
- Height: stand against a wall without shoes. Your height helps decide your jacket length.
Turning Your Numbers Into a Suit Size
Suit jackets in the US are usually labeled with a number and a letter, such as 40R or 42L.
- The number is based on your chest measurement in inches. A 40 inch chest generally means a size 40 jacket.
- The letter is the jacket length. As a general guide, S or Short fits men under about 5 feet 7 inches, R or Regular fits about 5 feet 8 inches to 6 feet, and L or Long fits about 6 feet 1 inch and up. These ranges vary by brand and by how long your arms and torso are.
- The drop is the difference between the jacket size and the trouser waist in a suit set. A common drop is 6 inches, so a 40R jacket often comes with 34 inch trousers.
Every brand cuts a little differently, so check your numbers against our size guide rather than relying on the size you wore from another store.
What If You Are Between Sizes
This is one of the most common questions people ask, and the answer depends on which part of the suit you are deciding on.
- For the jacket: choose the size that fits your shoulders and chest. A jacket that is slightly loose at the waist is easy to take in. A jacket that is too tight across the shoulders cannot be fixed.
- For the trousers: if the waist is between sizes, the larger size is usually the safer choice. Taking in a waist is a simple alteration. Letting one out depends on how much extra fabric is in the seam.
- If you have an athletic build with broad shoulders or a narrow waist, a standard drop may not fit you well. Separates or made to measure may be a better fit for your body.
Common Measuring Mistakes
- Using your jeans size for suit trousers. Jeans often sit lower and are labeled smaller than the real waist measurement.
- Pulling the tape too tight. Snug is right. Tight gives you numbers that are too small.
- Measuring your shoulders alone. Reaching behind yourself changes your posture and the result.
- Measuring over bulky clothing, which adds an inch or more.
- Guessing your height. Even an inch can change whether a Regular or Long jacket fits better.
How a Suit Should Fit When You Try It On
- Shoulders: the shoulder seam sits at the edge of your shoulder. No dent in the sleeve below the seam, and no fabric hanging past your shoulder.
- Chest: the jacket buttons without the fabric pulling into an X shape around the button.
- Jacket length: the jacket covers your seat, or most of it. With your arms at your sides, the hem usually lands around the middle of your hand.
- Sleeves: about a quarter to half an inch of shirt cuff shows below the jacket sleeve.
- Collar: the jacket collar rests against your shirt collar without a gap at the back of your neck.
- Trousers: they sit comfortably at your waist without a belt pulling them up, and the hem touches your shoes with a slight break or no break, depending on the look you want.
What a Tailor Can and Cannot Fix
Most suits bought off the rack benefit from a few small changes. Knowing what is easy to fix helps you choose the right size in the first place.
- Usually easy: hemming trousers, shortening sleeves, taking in the trouser waist, and slimming the jacket waist slightly.
- Sometimes possible: lengthening sleeves or trousers, depending on how much fabric is folded inside.
- Very hard or not worth it: changing the shoulders, making the jacket much longer or shorter, or adding room across the chest.
If your suit is for a wedding, plan to have it in hand at least three to four weeks before the date. That leaves time for a tailor visit and a second fitting if needed.
Measuring a Wedding Party
If you are coordinating suits for groomsmen who live in different cities, ask each person to measure with a helper and send their numbers, height, and weight in the same format. Collect everything in one shared sheet and double check any number that looks unusual before ordering. It also helps to order every suit at the same time so the colors match. You can see coordinated options in our groomsmen suits collection.
If You Are Ordering Made to Measure
A made to measure suit is cut from your own numbers, so careful measuring matters even more. After you order, our team emails you to confirm your measurements before production starts. Please read them carefully and reply if anything needs to change. Made to measure suits cannot be returned for a change of mind, but if the finished garment differs from your confirmed measurements by more than one inch, it is covered under our refund policy.
If the Fit Is Not Right When It Arrives
For ready to wear suits, you can return unworn, unaltered items within 30 days of delivery. We do not offer direct exchanges, so if you need a different size, start a return and place a new order for the size you need. If your event is close, we suggest placing the new order right away instead of waiting for the return to process. Full details are in our refund policy.
Frequently Asked Questions
What size suit am I if my chest is 42 inches?
Most likely a 42 jacket. Your height decides whether you need Short, Regular, or Long. Check the size guide for the exact range.
What does 40R mean in suits?
It means a jacket for a chest of about 40 inches, in a Regular length for men of roughly average height.
Should I size up or down if I am between sizes?
Choose the jacket that fits your shoulders, even if the waist is a bit loose. For trousers, the larger size is usually easier to tailor.
Is my suit pants size the same as my jeans size?
Often not. Suit trousers usually sit higher than jeans, so measure your waist where the trousers will sit.
How much shirt cuff should show below a suit sleeve?
About a quarter to half an inch.
Can I measure myself for a suit without help?
You can measure your waist and inseam alone, but shoulders and sleeves are far more accurate with a second person.
Putting It All Together
Fit is one of three choices that shape how your suit looks. The other two are fabric and color.
- Learn which fabrics suit your season and event in our suit fabric guide.
- Find a shade that works for your event and skin tone in our suit color guide.
When you have your numbers, browse our men' suits. If you are unsure which size to choose, email us at service@etevvu.com with your measurements, height, weight, and the suit you are looking at, and a real person on our team will help you pick a size.