Hi Matthew Females are not necessarily larger than males, they can be, but it's not the rule. Males will have larger heads and thicker tail bases than females (usually but not always). The adult beardie will weigh anywhere from 350 to 600 grams usually. As for the enclosure size, an adult beardie, whether male or female need no less than a 40 gallon breeder sized aquarium, larger is better. I built a 4 ft x 2 ft x 2 ft enclosure for $150 for the wood and all the supplies. A 20 gallon long is fine for a young dragon up to the length of 12", then you will have to put them in something larger. Beardies don't climb as much as other lizards do, so they need more floor space to move around. I hope this helps you :main_thumbsup: