Pipe Dimension Calculator
Convert nominal pipe sizes (NPS) to actual outside diameter (OD), inside diameter (ID), and wall thickness for steel, PVC, copper, and HDPE pipes. Find pipe dimensions instantly with our comprehensive lookup tool.
Select Pipe Specifications
Carbon steel pipe for general purpose applications
Higher schedule number = thicker wall, higher pressure rating
Nominal Pipe Size is a standard designation
Pipe Dimensions
Select pipe specifications and click
"Get Pipe Dimensions" to view results
What is Nominal Pipe Size (NPS)?
Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. The "nominal" designation means that the NPS is a dimensionless designator that doesn't directly correspond to the actual outside or inside diameter of the pipe.
For example, a 1-inch NPS steel pipe actually has an outside diameter of 1.315 inches, and the inside diameter varies depending on the wall thickness (schedule). This is why pipe sizing calculators are essential for accurate engineering work.
Key Points About NPS:
- NPS is a dimensionless designator, not an actual measurement
- For sizes up to NPS 12, the outside diameter (OD) is larger than the nominal size
- For sizes NPS 14 and above, the NPS equals the actual OD in inches
- The inside diameter (ID) depends on the wall thickness (schedule)
- Standards vary by material: steel (ASME), PVC (ASTM), copper (ASTM B88)
Understanding Pipe Schedules
Pipe schedule is a designation that indicates the wall thickness of a pipe. Higher schedule numbers mean thicker walls and higher pressure ratings. The most common schedules are Schedule 40 and Schedule 80.
Schedule Comparison
Schedule 40: Standard weight, most common for general purpose applications
Schedule 80: Extra strong, used for higher pressure or corrosive environments
Schedule 160: Double extra strong, for very high pressure applications
Important Notes:
- For a given nominal size, higher schedules have the same OD but thicker walls
- Thicker walls mean smaller inside diameter (less flow capacity)
- Schedule 40 and "Standard" (STD) are the same for sizes up to NPS 10
- Schedule 80 and "Extra Strong" (XS) are the same for many sizes
Common Pipe Dimensions
Steel Pipe Schedule 40 Dimensions
| NPS | OD (in) | ID (in) | Wall (in) |
|---|---|---|---|
| 1/2" | 0.840 | 0.622 | 0.109 |
| 3/4" | 1.050 | 0.824 | 0.113 |
| 1" | 1.315 | 1.049 | 0.133 |
| 1-1/4" | 1.660 | 1.380 | 0.140 |
| 1-1/2" | 1.900 | 1.610 | 0.145 |
| 2" | 2.375 | 2.067 | 0.154 |
| 3" | 3.500 | 3.068 | 0.216 |
| 4" | 4.500 | 4.026 | 0.237 |
PVC Pipe Schedule 40 Dimensions
| NPS | OD (in) | ID (in) | Wall (in) |
|---|---|---|---|
| 1/2" | 0.840 | 0.622 | 0.109 |
| 3/4" | 1.050 | 0.824 | 0.113 |
| 1" | 1.315 | 1.049 | 0.133 |
| 2" | 2.375 | 2.067 | 0.154 |
| 3" | 3.500 | 3.068 | 0.216 |
| 4" | 4.500 | 4.026 | 0.237 |
Note: PVC pipe uses Iron Pipe Size (IPS) dimensions, which match steel pipe OD.
How to Use This Calculator
- Select your pipe material - Choose from Steel (ASME B36.10M), PVC (ASTM D1785), Copper (ASTM B88), or HDPE (ASTM D3035)
- Choose the schedule or type - Options update automatically based on the material you selected. For steel/PVC use schedules (40, 80), for copper use types (K, L, M), and for HDPE use SDR ratings
- Select the nominal pipe size - Choose from standard NPS sizes ranging from 1/2" to 12" depending on the material
- Click "Get Pipe Dimensions" - View the actual OD, ID, wall thickness, and cross-sectional area in both imperial and metric units
Common Applications
- Steel Pipe: Industrial process, HVAC, fire protection, compressed air
- PVC Pipe: Water distribution, irrigation, drainage, low-pressure applications
- Copper Pipe: Plumbing, water supply, refrigeration, HVAC
- HDPE Pipe: Water mains, gas distribution, mining, industrial
Engineering Standards Reference
Steel Pipe
- Standard: ASME B36.10M, ASME B36.19M
- Material: Carbon steel, stainless steel
- Applications: General purpose, high pressure, high temperature
- Common Schedules: 40, 80, 160, STD, XS, XXS
PVC Pipe
- Standard: ASTM D1785, ASTM D2241
- Material: Polyvinyl chloride (PVC)
- Applications: Water supply, irrigation, drainage
- Common Types: Schedule 40, Schedule 80, SDR series
Copper Tube
- Standard: ASTM B88
- Material: Copper alloy
- Applications: Plumbing, HVAC, refrigeration
- Common Types: Type K, Type L, Type M, DWV
HDPE Pipe
- Standard: ASTM D3035, AWWA C906
- Material: High-density polyethylene
- Applications: Water/gas mains, industrial
- Common SDRs: SDR 11, SDR 17, SDR 21, SDR 26