Machining Calculators & Speeds and Feeds

The standard metric twist-drill stock series from 0.5 mm to 13 mm with the decimal-inch equivalent for each. These are true metric drills (3.0, 3.2, 3.5 mm…), not the millimetre conversions of inch drills — search a size to convert or compare.

Every 1/64" step from 1/64" to 1", with the decimal-inch and millimetre equivalent for each. Convert a fractional call-out to the decimal your caliper reads or the millimetres your CAD model uses. Search a fraction (3/8), a decimal (0.375), or a millimetre value.

Enter the number of holes, bolt circle diameter, and start angle — get the exact X/Y coordinate of every hole (inch or mm), clockwise or counter-clockwise, with a printable coordinate table and a scaled diagram for the shop floor.

Convert a cutting speed (SFM or m/min) and drill diameter into spindle RPM, and a feed per revolution into feed rate (in/min or mm/min) — with typical starting surface speeds by material.

Turn a cutting speed (SFM or m/min) and end-mill diameter into spindle RPM, and flute count + chip load (feed per tooth) into feed rate (in/min or mm/min) — with typical starting surface speeds and chip loads.

Convert either way between cutting/surface speed (SFM or m/min) and spindle RPM for a given diameter — the core relationship behind every speeds-and-feeds decision.

Find the extra tip length a twist drill's conical point adds, and the total depth to drill so the hole reaches full diameter at your target depth — for 118°, 135°, or any point angle.

From one chamfer leg and its angle, get the other leg and the chamfer face length — for 45° and any other angle, in inch or mm.

Enter any two of the sides or the angle of a right triangle and get the rest — the everyday shop trig for angled features, tapers, and layout.