Thread Calculator

Calculate thread dimensions for Unified (UN) and Metric (M) threads. Find major diameter, minor diameter, pitch diameter, and more.

Inches for UN, mm for Metric
TPI for UN, Pitch (mm) for Metric
Length of threaded section
Common Thread Standards
UNC (Coarse)1/4-20, 3/8-16
UNF (Fine)1/4-28, 3/8-24
Metric CoarseM6×1, M10×1.5
Metric FineM6×0.75, M10×1.25
UNEF (Extra Fine)1/4-32, 3/8-32
🔩 Thread Formulas:
Pitch: 1/TPI (UN)  •  Major Dia: Nominal Size  •  Pitch Dia: Major - 0.6495 × Pitch  •  Minor Dia: Major - 1.0825 × Pitch  •  UN: D = D - 1.0825P, d = D - 1.0825P
⚠️
Thread Analysis
📋

Step-by-Step Calculation

Detailed thread analysis

🔩
Major Dia
in
📐
Pitch Dia
in
📏
Minor Dia
in
Thread Class
📊

Thread Specifications

Complete thread dimensions

📖

Formula Reference

Thread formulas

💡

Thread Tips

Understanding thread dimensions

🔩 Engineering Disclaimer: Thread calculations are for standard Unified and Metric threads. Always verify with thread gauges and standards. Results are for educational purposes.
Thread Calculator  •  Major, Pitch, Minor Diameters  •  For educational purposes