Machinist Calculator has been developed to quickly solve common machine shop math problems such as trigonometry, speeds and feeds, bolt circles, and much more. Get your free demo now.

Drill Size Conversion Chart


This application will enable the user to quickly look up the decimal sizes of Number and Letter drills in the inch system.

Click the down arrow and use the drill charts to find the size needed. Click on the line to enter it into the diameter window.

This application opens ready to use the measuring system last used. If the metric system was used last, you'll be prompted to change to "Inch" for this function. You may also use the "Inch" and "Metric" options to convert values shown between Inch and Metric measurements.

Drill charts in spedd and feed calculator Download free Machinist's Calculator demo.