How thick must ice be for a single person to traverse?

• A. 2 inches
• B. 1 inch
• C. 3 inches
• D. 4 inches

Answer: (A)

Thickness is the primary factor in whether ice can safely bear a person’s weight, but other conditions matter too, like how clear the ice is, whether there’s current or thawing, and known weak spots. For a single person to traverse, the typical safety guideline is four inches of solid ice. Two inches is generally not enough and can give way under normal movement, so it’s not considered safe. Three inches is more risky and often treated as borderline rather than reliably safe. If you must be out on ice, test in several spots, avoid areas with current or visible cracks, never go alone, and carry safety gear and a plan in case you fall through.