1mm=1000um, so mm*1000=um easy way, move decimal three to the right 0.0082mm*1000=8.2um
You can make one yourself with Excel. Use the formula: Fahrenheit = Celsius x (9/5) + 32. Or just use the formula when you need it.
1 Ft. = .0001893939 Mile1 Mile = 5280 Ft
Multiply mm by 1,000 to get um. 67.5 mm = 67,500 um
mm-->in... divide by 25.4.... in-->mm... multiply by 25.4