A lot of discussion has occured regarding correct figure size. The chart below simplifies determining the actual size of a 1/30 figure in Millimeters. The average height of a man is 5'9", 69" or 1751 Millimeters. Dividing the size of the figure in Millimeters into 1751 gives the scale of the figure. Dividing the scale into 1751 gives the height the figure should be in Millimeters of a 5'9" man in that scale. The calculation also works for vehicles. The deck of a Tiger I is 1800mm high. Divided by 30 gives a scale deck height of 60mm.
..................................................Figure Size Conversion Chart
Figure Scale----------------------------Figure Height of 5'9' Man
1/72----------------------------------------------------24mm
1/48----------------------------------------------------36mm
1/56----------------------------------------------------31mm
1/35----------------------------------------------------50mm
1/32----------------------------------------------------54mm
1/30----------------------------------------------------58mm
1/28----------------------------------------------------62mm
1/27----------------------------------------------------65mm
1/26----------------------------------------------------67mm
1/25----------------------------------------------------70mm
1/24----------------------------------------------------73mm
..................................................Figure Size Conversion Chart
Figure Scale----------------------------Figure Height of 5'9' Man
1/72----------------------------------------------------24mm
1/48----------------------------------------------------36mm
1/56----------------------------------------------------31mm
1/35----------------------------------------------------50mm
1/32----------------------------------------------------54mm
1/30----------------------------------------------------58mm
1/28----------------------------------------------------62mm
1/27----------------------------------------------------65mm
1/26----------------------------------------------------67mm
1/25----------------------------------------------------70mm
1/24----------------------------------------------------73mm