Thread Calculator & Chart

Thread Calculator & Chart is the complete thread engineering and tap drill reference designed for machinists, CNC programmers, toolmakers, mechanical engineers, and workshop fabricators.

Get instant, accurate thread dimensions and recommended tap drill sizes across all major industrial thread standards. Whether you are setting up a CNC lathe, tapping a hole in the workshop, or designing precision threaded assemblies, Thread Calculator & Chart provides the exact geometry you need in seconds.

SUPPORTED THREAD STANDARDS:
- ISO Metric (Coarse and Fine pitch profiles, standard tolerance classes)
- Unified National Coarse (UNC)
- Unified National Fine (UNF)
- National Pipe Taper (NPT)
- British Standard Pipe (BSP - Parallel BSPP / G and Tapered BSPT / R)

KEY FEATURES & CAPABILITIES:
- Instant Thread Geometry: Calculate major diameter, pitch diameter, minor diameter, thread pitch, threads per inch (TPI), and basic thread depth.
- Recommended Tap Drill Sizes: Find the correct drill size for cut tapping and standard thread engagement.
- Searchable Reference Charts: Quickly browse standard thread sizes and drill tables with real-time filtering and search.
- Tolerance and Fit Classes: Explore internal and external thread specifications for precision fits.
- Saved Calculations: Save frequently used thread configurations with custom notes for quick reference during machining jobs.
- History Tracking: Revisit recent calculations without re-entering parameters.
- Engineering Guide: Access in-app diagrams and reference notes explaining thread profile formulas and geometry standards.

BUILT FOR PRECISION WORK:
Designed for high efficiency in active workshop environments. Clean, high-contrast typography and intuitive controls make finding thread dimensions fast, reliable, and straightforward.