If you've done photo jigsaws before, there's a simple rule: if you double the number of pieces, you increase the time needed by four! So if a 100-piece puzzle takes you 30 minutes, a 200-piece puzzle would take around two hours. It's widely suggested that a 500-piece puzzle will take the average person about five or six hours. Experienced puzzlers can complete a 1,000-piece jigsaw in about 10 hours but the average person might need up to 24 hours.