How big a table do you need for your jigsaw puzzle?

Jigsaw puzzles are typically labeled with their finished area and number of pieces. With this information, is it possible to estimate the area required to lay each piece flat before assembly? We derive a simple formula based on two-dimensional circular packing and show that the unassembled puzzle area is $\sqrt{3}$ times the assembled puzzle area, independent of the number of pieces. We perform measurements on 9 puzzles ranging from 333 cm$^2$ (9 pieces) to 6798 cm$^2$ (2000 pieces) and show that the formula accurately predicts realistic assembly scenarios.