Free drilling calculators

Quick answers for the numbers people look up most when drilling: how fast to run the bit, which bit to use for a wood screw, and which bit to use before tapping a thread. Each calculator also shows its full chart, so it works without JavaScript and you can print it.

• Drill speed (RPM) calculatorThe right RPM for a bit size and material: steel, stainless, aluminum, cast iron, brass and plastic.
• Pilot hole calculatorPilot and clearance hole sizes for wood screws #2 to #14 in softwood and hardwood.
• Framing nail angle checkerWhether 21, 22, 28, 30 or 34 degree nails fit your framing nailer.
• Tap drill calculatorThe drill size for any UNC, UNF or metric thread, with the nearest fractional, number, letter and metric bits.

Need paper copies for the workshop? See the printable charts.

For every drill size in fractional, number, letter and metric, see the drill bit size chart.