Pipe Schedule Calculator

Quick Answer

• NPS (Nominal Pipe Size) → Standard pipe size designation
• DN (Nominal Diameter) → Metric equivalent
• SCH (Schedule) → Wall thickness level
• Output = OD + Wall Thickness

How to Use

1. Select Nominal Pipe Size (NPS)
2. Select corresponding DN (metric size)
3. Choose Pipe Schedule (SCH)
4. Instantly get:
   • Outer Diameter (OD)
   • Wall Thickness (THK)

👉 No manual lookup needed from tables

What Each Parameter Means

NPS (Nominal Pipe Size)

• North American standard size system
• Does NOT equal actual OD
• Example:
  • NPS 1/2 → OD = 21.3 mm

DN (Nominal Diameter)

• Metric designation
• Rough equivalent to NPS
• Used in international projects

Pipe Schedule (SCH)

• Defines wall thickness
• Common schedules:
  • SCH 10 → thin wall
  • SCH 40 → standard
  • SCH 80 → thick wall

Standard Reference

This calculator is based on:

• ASME B36.10M (Carbon Steel Pipes)
• ASME B36.19M (Stainless Steel Pipes)

Engineering Insight

OD is Fixed (for same NPS)

For a given NPS:

• OD stays constant
• Wall thickness changes with SCH

Example

• NPS: 1/8
• DN: 6
• SCH: 40

👉 Result:

• OD ≈ 10.29 mm
• Wall thickness ≈ 1.73 mm

Common Pipe Size Table (Reference)

When to Use This Tool

• Pipe system design
• Pressure piping calculations
• Material estimation
• Procurement & quoting
• CAD modeling reference

Design Tips

Choosing Pipe Schedule

• Low pressure → SCH 10 / 20
• General use → SCH 40
• High pressure → SCH 80+

Avoid Common Mistakes

• NPS ≠ actual diameter
• DN is not exact conversion
• Always check schedule for thickness

FAQ

What is NPS?

A standardized pipe size system used mainly in the US.

What does SCH mean?

Schedule defines pipe wall thickness.

Is OD always constant?

Yes, for the same NPS.

Can I use DN instead of NPS?

DN is metric equivalent, but standards differ slightly.

Which standard should I follow?

Use ASME B36.10M or B36.19M depending on material.