Hamilton Murph 38mm vs 42mm: Which Size Should You Buy?

Same watch, two sizes. The movement, crystal, water resistance and caseback are identical — the 42 mm is 4 mm wider, 22 mm at the lugs and costs $100 more. Buy the 38 mm if your wrist is under about 7 inches; buy the 42 mm if you want the proportions the film used.

Hamilton released the Murph at 42 mm in 2019 and added the 38 mm later, after — in its own words — the community asked for it. The two are not a compromise and a flagship. They are the same design at two scales, and the choice is almost entirely about your wrist.

The specification sheets are nearly identical: the H-10 automatic with its 80-hour reserve, a Nivachron balance spring, sapphire with anti-reflective treatment, 100 m of water resistance and an exhibition caseback appear on both. Thickness is effectively the same — 11 mm on the 42, 11.1 mm on the 38. What changes is footprint: 42 mm across and 22 mm at the lugs against 38 mm and 20 mm, and a 53 mm lug-to-lug on the larger case that Hamilton publishes but does not publish for the smaller one. The $100 difference is not the deciding factor. If you have ever taken a 42 mm watch off because it overhung your wrist, the 38 mm is the one to buy, and it loses you nothing mechanically.