Internal Diameter (ID) Calculator
This calculator helps you determine the internal diameter (ID) of any pipe, tube, or hollow cylinder. The internal diameter is a critical measurement in engineering, plumbing, and manufacturing, as it directly affects factors like fluid flow capacity, pressure ratings, and compatibility with fittings.
How to Calculate Internal Diameter
The calculation for internal diameter is straightforward. It is derived from two primary measurements: the outer diameter (OD) and the wall thickness (WT) of the object. The formula is:
Internal Diameter (ID) = Outer Diameter (OD) – (2 × Wall Thickness)
You subtract twice the wall thickness from the outer diameter because the wall exists on both sides of the central void when measured across the diameter.
Practical Example
Imagine you have a steel pipe with an outer diameter of 100mm and a wall thickness of 5mm. To find the internal diameter:
- Outer Diameter (OD): 100 mm
- Wall Thickness (WT): 5 mm
- Calculation: ID = 100mm – (2 × 5mm)
- Result: ID = 100mm – 10mm = 90 mm
The available space inside the pipe for fluid to flow through is 90mm across.
Calculate ID
Ensure both values use the same unit (e.g., mm, inches). The result will be in the same unit.