Thread pitch and TPI calculator
Thread pitch and TPI calculator
Convert TPI to metric thread pitch or pitch to TPI, including thread counts over 10 mm and one inch. Inputs, formula and interpretation are separated so you can verify the result before using it for a configurable part.
Calculate
Schematic illustration – not to scale.
Schematic illustration – not to scale.
Formula
pitch_mm = 25.4 / TPI; TPI = 25.4 / pitch_mm
Thread values are calculation aids. Metric and Unified threads are not automatically compatible.
Step by step
- Enter the measured or planned values with their units.
- Check the formula with substituted values in the result area.
- Copy the parameters or open a related product for configuration.
Complete worked example
Worked example with typical workshop values: insert the inputs, apply pitch_mm = 25.4 / TPI; TPI = 25.4 / pitch_mm and compare the result with the reference table.
| 2 | 30 | 60 mm |
| 1 | 40 | 40 mm |
| 3 | 20 | 60 mm |
Assumptions and limitations
- Thread values are calculation aids. Metric and Unified threads are not automatically compatible.
Common input mistakes
- Decimal comma and point are accepted, but do not type units into numeric fields.
- For gears, the tooth count must be a whole number in practice.
FAQ
Are metric and UNC/UNF threads interchangeable?
No. Similar diameters do not mean profile, pitch and tolerance are compatible.
Can I manufacture directly from this result?
Use the value as a calculation and configuration aid. Loaded or standards-critical parts need engineering review.
Related products
PipeConfigure a custom pipe online and adjust Outer diameter, Inner diameter and Length to your application.
Configure product
Closed 3-way pipe connectorConfigure a custom closed 3-way pipe connector online and adjust Inner diameter, Wall thickness and Depth to your application.
Configure product
Pipe bendConfigure a custom pipe bend online and adjust Inner diameter, Outer diameter, Angle and Arc length along the centerline to your application.
Configure product
Hollow threaded spindleConfigure a custom hollow threaded spindle online and adjust Specific dimension to your application.
Configure product
Double-thread adapterConfigure a custom double-thread adapter online and adjust Specific dimension to your application.
Configure product
Threaded plugConfigure a custom threaded plug online and adjust Specific dimension and Bore diameter to your application.
Configure product