Fractional Decimal Metric Chart

Fractional Decimal Metric Chart

Printing it out

Having your printer ‘scale to fit’ your Letter or A4 paper shouldn’t matter, but the numbers are 9 pt font size, so too much reduction will make it hard to read, whereas a larger scaled print might be great for your studio/shop wall.  I keep it under my keyboard.

Using the Conversion chart


Rows contain equivalent measurements; 1/64th = .015625 = 0.4m
Columns are the systems:  Fractional English, Decimal English and Metric.

  1. Start with your system at top: Eng, 16ths, 32nds, 64ths, Dec. Inch, Millimeters
  2. drop down to your starting  dimension
  3. read left/right for equivalents and up/down for close measurements (smaller, larger.)


  • The chart is English-centric, millimeters are rounded to the tenth.  In my work 1/10th of a millimeter ain’t much. I’ll post a mm-centric version if asked.
  • I removed denominators to make the chart smaller, and to visually clarify relationships between adjacent numbers, this may take some getting used to.
  • To convert a dimension read left or right of your given number in the same row. 3/16” –> .1875”  –> 4.8mm

Workshop Examples:


A. Can I drill for a 6mm-fine screw tap with only my English drill set?
A 5mm drill is needed for optimal thread pentration.

  • 3/16″ might go, with careful tapping.
  • 13/64″ could work, but would be loose (poor thread pentration.)

B. Need the closest English dado to 18mm plywood

  • .703125″ … would be press-fit, may not go, unless ply is undersized.
  • 23/32″ could be great for glueline & assembly

C. How much bigger or smaller are the adjacent 64ths to 3/32 ?

  • 5/64 is .078 or 20% smaller (with calculator)
  • 7/64 is .109 or  16% larger (with calculator)