Crab legs are generally fine to eat a few times a week as part of a balanced diet, and many seafood guidelines place crab in the lower-mercury category. One source notes that lower-mercury seafood such as crab can fit into about two to three 4-ounce servings per week for pregnancy, while general seafood guidance suggests at least two seafood meals weekly overall.

Practical rule of thumb

  • For most healthy adults, eating crab legs 1–3 times per week is a reasonable pattern.
  • Keep portions moderate, especially if the crab is heavily salted, buttered, or served with rich sauces.
  • If you eat seafood often, rotate in different types rather than having crab every day.

When to be more careful

  • If you have kidney issues, high blood pressure, or sodium restrictions , watch the seasoning and portion size.
  • If you are pregnant, the lower-mercury guidance for crab is more permissive than for high-mercury fish, but variety still matters.
  • If you have a shellfish allergy, crab legs should be avoided entirely.

Simple answer

If you just want the short version: crab legs are usually okay once or twice a week , and often up to a few times weekly depending on the rest of your diet.

A quick example

A normal pattern might be: crab legs for dinner on Saturday, another seafood meal midweek, and other proteins the rest of the week. That keeps things balanced without overdoing shellfish. Information gathered from public web sources and summarized here.