A simple scale for architects or engineers in both metric and imperial systems.
Metric system scale: 1:1/1:100, 1:2/1:200, 1:5/1:500, 1:10/1:1000, 1:20/1:2000, 1:50/1:5000, 1:1250, 1:2500.
Imperial system scale: 1, 1-1/2, 3/4, 1/2, 3/8, 1/4, 3/16, 1/8