Hermit Crab Sizing Circle Chart

Why does size matter? When determining how much space is needed per hermit crab we need to know how large the crabs are and how large they will grow. Small crabs can be happy in a smaller habitat while jumbo crabs need a minimum of 15 gallons per crab. More than 10G/crab is always better! A hermit crab must live many decades to reach jumbo size.

Updated for 2025 for increased accuracy!

This updated PDF includes updated charts and printing instructions.

Use a piece of string our something similar to measure the second walking leg in centimetres. Compare to the chart to determine the size. Your combined results should give a more accurate size.