Copper Pipe & Tubing Sizes Chart
Complete reference charts for Type K, L, and M copper pipe and tubing dimensions. Find OD, ID, wall thickness, and flow area for all standard sizes per ASTM B88.
Type K Copper Pipe Size Chart
Heavy wall copper tubing with the thickest walls and highest pressure rating. Commonly used for underground water service, high-pressure HVAC, and refrigeration systems.
| Nominal Size | OD (in) | OD (mm) | ID (in) | ID (mm) | Wall (in) | Wall (mm) | Area (in²) |
|---|---|---|---|---|---|---|---|
| 1/2" | 0.625" | 15.90 | 0.527" | 13.40 | 0.049" | 1.24 | 0.218 |
| 3/4" | 0.875" | 22.20 | 0.745" | 18.90 | 0.065" | 1.65 | 0.436 |
| 1" | 1.125" | 28.60 | 0.995" | 25.30 | 0.065" | 1.65 | 0.778 |
| 1-1/4" | 1.375" | 34.90 | 1.245" | 31.60 | 0.065" | 1.65 | 1.217 |
| 1-1/2" | 1.625" | 41.30 | 1.481" | 37.60 | 0.072" | 1.83 | 1.723 |
| 2" | 2.125" | 54.00 | 1.959" | 49.80 | 0.083" | 2.11 | 3.014 |
| 3" | 3.125" | 79.40 | 2.907" | 73.80 | 0.109" | 2.77 | 6.637 |
| 4" | 4.125" | 104.80 | 3.857" | 98.00 | 0.134" | 3.40 | 11.684 |
Standard: ASTM B88 - Type K (Heavy Wall)
Type L Copper Pipe Size Chart
Medium wall copper tubing - the most common type for residential and commercial plumbing. Suitable for interior water supply, HVAC systems, and general plumbing applications.
| Nominal Size | OD (in) | OD (mm) | ID (in) | ID (mm) | Wall (in) | Wall (mm) | Area (in²) |
|---|---|---|---|---|---|---|---|
| 1/2" | 0.625" | 15.90 | 0.545" | 13.80 | 0.040" | 1.02 | 0.233 |
| 3/4" | 0.875" | 22.20 | 0.785" | 19.90 | 0.045" | 1.14 | 0.484 |
| 1" | 1.125" | 28.60 | 1.025" | 26.00 | 0.050" | 1.27 | 0.825 |
| 1-1/4" | 1.375" | 34.90 | 1.265" | 32.10 | 0.055" | 1.40 | 1.257 |
| 1-1/2" | 1.625" | 41.30 | 1.505" | 38.20 | 0.060" | 1.52 | 1.779 |
| 2" | 2.125" | 54.00 | 1.985" | 50.40 | 0.070" | 1.78 | 3.095 |
| 3" | 3.125" | 79.40 | 2.945" | 74.80 | 0.090" | 2.29 | 6.812 |
| 4" | 4.125" | 104.80 | 3.905" | 99.20 | 0.110" | 2.79 | 11.977 |
Standard: ASTM B88 - Type L (Medium Wall)
Type M Copper Pipe Size Chart
Thin wall copper tubing for low-pressure residential applications. Economical choice for above-ground water distribution and drain waste vent (DWV) systems.
| Nominal Size | OD (in) | OD (mm) | ID (in) | ID (mm) | Wall (in) | Wall (mm) | Area (in²) |
|---|---|---|---|---|---|---|---|
| 1/2" | 0.625" | 15.90 | 0.569" | 14.50 | 0.028" | 0.71 | 0.254 |
| 3/4" | 0.875" | 22.20 | 0.811" | 20.60 | 0.032" | 0.81 | 0.517 |
| 1" | 1.125" | 28.60 | 1.055" | 26.80 | 0.035" | 0.89 | 0.874 |
| 1-1/4" | 1.375" | 34.90 | 1.291" | 32.80 | 0.042" | 1.07 | 1.309 |
| 1-1/2" | 1.625" | 41.30 | 1.527" | 38.80 | 0.049" | 1.24 | 1.831 |
| 2" | 2.125" | 54.00 | 2.009" | 51.00 | 0.058" | 1.47 | 3.170 |
| 3" | 3.125" | 79.40 | 2.981" | 75.70 | 0.072" | 1.83 | 6.979 |
| 4" | 4.125" | 104.80 | 3.935" | 99.90 | 0.095" | 2.41 | 12.161 |
Standard: ASTM B88 - Type M (Thin Wall)
About Copper Pipe Types (K, L, M)
Copper pipe and tubing is classified into three main types based on wall thickness: Type K (heavy), Type L (medium), and Type M (thin). All three types have the same outside diameter for a given size, but differ in wall thickness, which affects pressure rating, cost, and applications.
Type K - Heavy Wall
- Wall Thickness: Thickest (0.049" - 0.134")
- Inside Diameter: Smallest
- Pressure Rating: Highest
- Weight: Heaviest
- Cost: Most expensive
- Color Code: Green marking
- Applications: Underground service, high-pressure HVAC, refrigeration
Type L - Medium Wall
- Wall Thickness: Medium (0.040" - 0.110")
- Inside Diameter: Medium
- Pressure Rating: Medium-high
- Weight: Moderate
- Cost: Moderate
- Color Code: Blue marking
- Applications: Interior plumbing, residential/commercial water supply
Type M - Thin Wall
- Wall Thickness: Thinnest (0.028" - 0.095")
- Inside Diameter: Largest (more flow capacity)
- Pressure Rating: Lower than K & L
- Weight: Lightest
- Cost: Least expensive
- Color Code: Red marking
- Applications: Low-pressure residential, above-ground DWV
Important Note:
Unlike steel pipe which uses Nominal Pipe Size (NPS), copper tubing is sized by its actual outside diameter. For example, "1/2 inch copper" has an actual OD of 0.625 inches, not a nominal size. This is crucial when sizing fittings and calculating flow areas.
How to Read This Chart
Column Definitions
- Nominal Size
- The standard reference size (e.g., 1/2", 3/4", 1"). For copper, this represents the actual outside diameter.
- OD (Outside Diameter)
- Actual external diameter of the pipe. Same for all types (K, L, M) for a given size. Shown in both inches and millimeters.
- ID (Inside Diameter)
- Internal diameter available for fluid flow. Varies by type - Type K has smallest ID, Type M has largest ID. Shown in both inches and millimeters.
- Wall Thickness
- Thickness of the pipe wall. Type K (thickest) → Type L (medium) → Type M (thinnest). Formula: Wall = (OD - ID) / 2. Shown in both inches and millimeters.
- Area (Flow Area)
- Cross-sectional area available for fluid flow, calculated as π × (ID/2)². Used in flow rate and velocity calculations. Shown in square inches.
How to Select the Right Type
- Check your application requirements - Consider pressure, temperature, location (above/underground), and local building codes.
- Determine required pressure rating - Type K for high pressure, Type L for medium, Type M for low pressure.
- Consider installation location - Underground applications typically require Type K due to soil loads and corrosion.
- Review code requirements - Some local codes mandate minimum types for specific applications.
- Calculate flow requirements - Use our Flow Rate Calculator to ensure adequate capacity.
Copper Pipe Applications by Type
Type K Applications
- Underground water service lines
- High-pressure HVAC systems
- Refrigeration lines
- Fire protection systems
- Industrial process piping
- Fuel oil lines
- Compressed air systems
- Natural gas distribution
Type L Applications
- Residential water supply (most common)
- Interior plumbing systems
- Commercial building water systems
- HVAC chilled water lines
- Hot water heating systems
- Medical gas systems
- Solar heating systems
- Pool and spa plumbing
Type M Applications
- Low-pressure residential water lines
- Above-ground distribution
- Drain waste vent (DWV) systems
- Vacuum systems
- Non-potable water systems
- Hydronic heating (low pressure)
- Condensate return lines
- General plumbing (where codes allow)
Temperature & Pressure Considerations:
Copper tubing pressure ratings decrease as temperature increases. Always apply appropriate de-rating factors for elevated temperatures. Maximum recommended temperature for water systems is typically 180°F (82°C). For refrigeration and HVAC applications, consult specific pressure-temperature tables.
Standards & Specifications
ASTM B88 Standard
ASTM B88 is the primary standard for seamless copper water tube. It specifies dimensions, tolerances, and material requirements for copper tube intended for water, air, and other fluids in plumbing, heating, air conditioning, refrigeration, and other systems.
- Type K: Heaviest wall thickness, suitable for underground and high-pressure applications
- Type L: Medium wall thickness, general purpose interior plumbing
- Type M: Lightest wall thickness, economical choice for low-pressure applications
Temper Classifications
Hard Drawn (Rigid)
Manufactured in straight lengths (typically 20 feet). Rigid copper requires fittings for all directional changes. Used for straight runs and structural applications. Common for Type K, L, and M water lines.
Soft Annealed (Flexible)
Manufactured in coils (25, 50, 60, 100 feet). Can be bent by hand, reducing fitting requirements. Ideal for tight spaces and underground installation. Available in all types but most common in refrigeration and water service applications.
Common Designations
- ACR (Air Conditioning & Refrigeration): Cleaned, dehydrated, sealed with nitrogen. Used for HVAC and refrigeration systems. Available in Types K, L, and M.
- DWV (Drain Waste Vent): Type M copper for non-pressure drainage systems. Lighter wall thickness suitable for gravity-fed waste lines.
- Medical Gas: Specially cleaned Type K or L copper for medical gas distribution systems. Must meet stringent purity requirements.
Material Properties
- Material: Pure copper (C12200 alloy) - 99.9% copper minimum
- Thermal Conductivity: 226 BTU/(hr·ft·°F) - Excellent heat transfer
- Coefficient of Expansion: 0.0000094 in/in/°F
- Corrosion Resistance: Excellent in most environments
- Joining Methods: Soldering, brazing, compression fittings, press fittings
- Maximum Operating Temperature: 180°F (water), 400°F (refrigerant)
Related Calculators
Engineering Notes & Disclaimer
Standards Compliance: All dimensions in this chart are based on ASTM B88 (Standard Specification for Seamless Copper Water Tube).
Pressure Ratings: Pressure ratings vary by type, temperature, and size. Always consult manufacturer specifications, ASTM standards, and applicable codes for pressure rating information.
Temperature De-rating: Copper tubing pressure ratings decrease significantly at elevated temperatures. Apply appropriate de-rating factors for temperatures above 100°F.
Installation: Proper installation practices are critical for system performance and safety. Follow manufacturer guidelines for joining methods, support spacing, and expansion compensation.
Code Compliance: Always verify compliance with local plumbing codes (IPC, UPC), mechanical codes, and building codes. Some jurisdictions mandate minimum types for specific applications.
Professional Verification: This chart is for reference and preliminary design only. All piping systems must be designed and verified by qualified engineers in accordance with applicable codes, standards, and local regulations. Always verify dimensions and specifications with manufacturer data sheets.
Liability: The user assumes all responsibility for proper application of this information. PipeSizing.net and its operators are not liable for any damages or losses resulting from the use of this chart.