Standard imperial sizes-generally 1 3/8″ thickness = 35mm.

INCHES METRIC mm
15″ x 78″ 381mm x 1981mm
18″ x 78″ 457mm x 1981mm
21″ x 78″ 533mm x 1981mm
24″ x 78″ 610mm x 1981mm
27″ x 78″ 686mm x 1981mm
28″ x 78″ 711mm x 1981mm
30″ x 78″ 762mm x 1981mm
33″ x 78″ 838mm x 1981 mm
32″ x 80″ 813mm x 2032mm
36″ x 78″ 914mm x 1981 mm
42″ x 78″ 1067mm x 1981 mm
46″ x 78″ 1168mm x 1981 mm
48″ x 78″ 1219mm x 1981 mm
54″ x 78″ 1372mm x 1981 mm
60″ x 78″ 1524mm x 1981 mm

Standard metric sizes-generally 40mm thickness = 1 5/8″.

METRIC mm INCHES
526mm x 2040mm 20 3/4″ x 80 1/4″
626mm x 2040mm 24 5/8″ x 80 1/4″
726mm x 2040mm 28 5/8″ x 80 1/4″
826mm x 2040mm 32 1/2″ x 80 1/4″
926mm x 2040mm 36 1/2″ x 80 1/4″

External doors- imperial (feet & inches)

Standard imperial sizes-generally 1 3/4″ thickness = 44mm.

INCHES METRIC mm
30″ x 78″ 762mm x 1981mm
33″ x 78″ 838mm x 1981 mm
32″ x 80″ 813mm x 2032mm
33″ x 81″ 838mm x 2057mm
82″ x 34″ 863mm x 2083mm
84″ x 36″ 914mm x 2134mm

Door Size Conversion

INCHES METRIC mm FEET & inches
15 381 1′ 3″
18 457 1′ 6″
21 533 1′ 9″
24 610 2′
27 686 2′ 3″
28 711 2′ 4″
30 762 2′ 6″
32 813 2′ 8″
33 838 2′ 9″
34 863 2′ 10″
36 914 3′
42 1067 3′ 6″
46 1168 3′ 10″
48 1219 4′
54 1372 4′ 6″
60 1524 5′
HEIGHT
78 1981 6′ 6″
80 2032 6′ 8″
81 2057 6′ 9″
82 2083 6’10”
84 2134 7′
METRIC mm INCHES
526
20 3/4″
626
24 5/8″
726
28 5/8″
826
32 1/2″
926
36 1/2″
HEIGHT
2040
80 1/4″