How to Measure Jacket Length:
For Suits, Sport Coats, and Blazers

A classic two-button suit jacket should reach the second knuckle of your thumb when your arm hangs naturally. For a 5'10" man this is roughly 30-31 inches from the base of the back collar. Modern slim cuts run 0.5-1 inch shorter; tuxedos run 0.5 inch longer. The jacket should always cover the seat (the bottom hem reaches at least the bottom of the buttocks).

A sport coat or blazer follows the same length rules as a suit jacket — second knuckle of the thumb for classic cuts, half an inch shorter for modern cuts. There is no separate "sport coat length" rule.

Almost never. Jacket length can be shortened by 1-1.5 inches by taking up the hem, but extending it requires the original hem allowance to be available — and most factory and MTM jackets allow only 0.5 inch of additional length. Always order slightly long if in doubt; you can shorten, not lengthen.

The 2026 menswear trend has pulled back from the extreme cropped silhouette of 2018-2022 toward a balanced classical length. The modern target is the second knuckle of the thumb to half an inch above — covering the seat, ending at or just above the wrist bone, and always avoiding the cropped above-wrist look that now reads as dated.

Tall men with short legs need a slightly shorter jacket to balance proportions. Short men with long legs sometimes need a slightly longer jacket. The thumb-knuckle rule self-adjusts for these cases — but for unusual builds, a tailor draws the target with you in front of a mirror rather than measuring blind.

The bottom hem should reach at least the bottom of the buttocks (the gluteal fold) when standing naturally. A jacket that ends above the seat looks cropped; one that goes more than 0.5 inch below the seat looks long. Modern cuts typically end at the gluteal fold; classic cuts end 0.5 inch below.