101 free calculators and engineering references for CNC programmers, machinists, estimators, and manufacturing engineers.
23 calculators — Speeds & feeds, chip load, SFM, MRR, cycle time, horsepower, cutting force, surface roughness, and tool path geometry
17 calculators — Tap drill size, tapping feed rate, drill point length, thread pitch, NPT pipe thread, peck drilling, countersink, reaming, and gun drilling
21 tools — Hardness converter, metal weight & cost, machinability, carbide grades, stainless properties, titanium guide, aluminum alloys, and coating selector
40 tools — Cost per part, batch cost, CNC ROI, OEE, tool life economics, ISO fits, bolt circle, GD&T, G-code ref, unit converters, and shop planning calculators
These 101 tools are built for practicing machinists, CNC programmers, manufacturing engineers, estimators, and shop owners. Every calculator uses engineering-standard formulas from ISO, ASME, and industry references — the same math behind Sandvik Coromant ToolGuide, Kennametal NOVO, and Machinist's Handbook tables.
Yes, all 101 calculators and reference tools are completely free. No registration, no paywall, no trial period. Bookmark the ones you use most.
All calculators use standard engineering formulas from ISO, ASME, and industry references. Results are accurate for theoretical calculations. Real-world results vary with machine rigidity, tool condition, coolant, and material batch variation — always verify with a test cut.
This is a web-based tool collection. You can save individual calculator pages for offline use in most browsers (Ctrl+S / Cmd+S). For shop-floor use, we recommend bookmarking on your phone or tablet.
Yes. If you need a specific CNC calculator that is not here, contact us with the formula or use case. We add new tools regularly based on user requests.