Men's Suit Size Table
| Chest size | Drop-6 waist | Drop-7 waist | Height band |
|---|---|---|---|
| 36 | 30 | 29 | S/R by height |
| 38 | 32 | 31 | S/R by height |
| 40 | 34 | 33 | R typical |
| 42 | 36 | 35 | R typical |
| 44 | 38 | 37 | R/L by height |
| 46 | 40 | 39 | L common |
| 48 | 42 | 41 | L common |
| 50 | 44 | 43 | L/XL |
A men's suit size is two numbers and a letter: chest in even inches (38, 40, 42...), the drop (how many inches smaller the trouser waist is than the chest - usually 6 or 7), and a length letter for the jacket (S, R, L by height). The table below maps chest sizes 36 through 50 to their drop-6 and drop-7 trouser waists and the height bands for each length letter.
Bottom line: a 40R means a 40-inch chest jacket, a 34-inch drop-6 trouser, and a Regular jacket cut for roughly 5'7" to 6'0" - and the chest is measured around the fullest part, not the neck or the fantasy waist. Between sizes, the shoulders decide: shoulder seams that overhang cannot be tailored shorter, while almost everything else (sleeves, waist, length) can.
The honest part: the drop system quietly assumes a chest-to-waist difference of 6-7 inches, which fits fewer bodies than the racks suggest - athletic builds with 9-inch drops need trousers tailored separately (many suits ship with unfinished waists exactly for this), and heights under 5'5" or over 6'3" are better served by made-to-measure than by the S/L extremes of any rack.
How to use
- Measure chest around the fullest part, tape level under the arms, arms down, breathing normally - round up to the nearest even number.
- Measure natural waist at the navel; the difference decides your drop (6-inch difference = drop 6, 7 = drop 7).
- Pick the length letter by height - S under 5'7", R from 5'7" to 6'0", L over 6'0" - then check the standover of the jacket's hem at the seat.
Frequently asked questions
What does the R in 40R mean?
Regular jacket length - cut for a man about 5'7" to 6'0" tall. S (Short) suits heights under about 5'7", L (Long) over 6'0", and some brands add XL for past 6'4". The letter controls jacket and sleeve length, not the chest: a 40S, 40R and 40L all wrap the same chest, so height decides the letter while chest decides the number - and getting both right is why suits are the one menswear item genuinely worth a fitting room.
What does drop 6 or drop 7 mean on a suit?
The drop is how many inches smaller the trouser waist is than the jacket chest: a drop-6 40R ships with 34-inch trousers, drop-7 with 33. The system assumes a V-shaped torso, which fits some men perfectly and others not at all - a swimmer's 8-10 inch drop needs a smaller trouser than any rack pairing, which is why suits are commonly sold with unfinished trouser waists for separate tailoring. Measure your natural waist and check the arithmetic before assuming your usual trouser size carries over.
How is a suit supposed to fit in the shoulders?
The shoulder seam must end exactly at the edge of your shoulder bone - this is the one measurement tailoring cannot fix, because moving a shoulder seam means rebuilding the jacket. Everything else is negotiable: sleeves can be shortened from the cuff end, the waist can be taken in, the jacket length can come up a little. If the shoulder seam droops past your arm or pinches inward, try a different chest size even if the waist feels loose - the waist is a $40 alteration; the shoulders are a new jacket.
Should I buy the suit bigger to allow for alterations?
No - buy the correct chest and shoulders, because there is nothing to gain: alterations take fabric in or let it out at the seams, and letting out works only if the maker left allowance (usually under an inch). Buying a 42 when you measure a 40 does not create useful extra fabric - it adds it in the wrong places, and taking a whole size down costs more tailoring than the suit is worth. The one deliberate oversize: trousers with unfinished waists, sized to be taken in.