It takes 5 to 7 years for a lobster to grow to legal size or about one pound.
To reach one pound of weight, it takes 5-7 years. The legal size for catching lobster is based on the physical size of the lobster, but legally sized lobsters are normally close to one pound. Lobsters that have not reached the legal size are returned to the water. This limit is vigorously enforced in Prince Edward Island, and is a key component of ensuring the lobster fishery is sustainable.