Inches = Millimeters Inches = Millimeters 25 1/2" - 650 mm. 6 3/4" - 170 mm. 24 1/2" - 622 mm. 6 1/2" - 162 mm. 23.6" - 600 mm. 6 1/4" - 159 mm. 21" - 533 mm. 6.1" - 155 mm. 19.7" - 500 mm. 6" - 152 mm. 18.1" - 460 mm. 5.9" - 150 mm. 18" - 457 mm. 5 3/4" - 147 mm. 17. 7 " - 450 mm. 5 1/2" - 138-140 mm. 17 1/2" - 445 mm. 5.3" - 135 mm. 17" - 432 mm. 5 1/4" - 133 mm. 16 1/4" - 410 mm. 5.1" - 130 mm. 16" - 406 mm. 5" - 127 mm. 15 3/4" - 400 mm. 4 3/4" - 120 mm. 15" - 380-381 mm. 4.7" - 120 mm. 14" - 356 mm. 4 1/2" - 114 mm. 13 3/4" - 350 mm. 4 1/4" - 108 mm. 13 1/2" - 343 mm. 4.1" - 105 mm. 13.4" - 340 mm. 4" - 102 mm. 13" - 330 mm. 3.9" - 100 mm. 12 3/4" - 324-325 mm. 3 3/4" - 98 mm. 12.6" - 320 mm. 3.6" - 90 mm. 12 1/2" - 318-320 mm. 3 1/2" - 89 mm. 12 1/4" - 310 mm. 3.4" - 88 mm. 12" - 305 mm. 3 1/4" - 80 mm. 11 3/4" - 300 mm. 3" - 75-76 mm. 11" - 279-280 mm. 2 3/4" - 69-70 mm. 10 3/4" - 270 mm. 2 1/2" - 63-64 mm. 10" - 254 mm. 2 1/4" - 57 mm. 9 3/4" - 250 mm. 2" - 51 mm. 9 1/2" - 241 mm. 1 3/4" - 45 mm. 9" - 229-230 mm. 1 1/2" - 38 mm. 8 3/4" - 225 mm. 1 1/4" - 32 mm. 8" - 203 mm. 1.1" - 28 mm. 7" - 178 mm. 1" - 25 mm.