Standard 1-1/4" nominal Type L copper tubing has an ASTM B88 calibrated inside diameter of 1.265 inches, holding 0.0653 US gallons (0.811 liters per meter) per linear foot. Part of our Copper Pipe Volume Hub and universal Pipe Volume Calculator suite.
Calculations are based on cylindrical formula \(V = \pi r^2 L\). Verify dimensions against manufacturer specs for code submittals.
Instant capacity and weight lookup table for common copper pipe runs filled with potable water at 60°F.
| Pipe Length (Ft) | US Gallons | Liters | Cubic Feet (ft³) | Water Weight (lbs) | Dry Copper (lbs) | Total Wet Weight |
|---|---|---|---|---|---|---|
| 1 ft | 0.065 gal | 0.25 L | 0.009 ft³ | 0.5 lbs | 0.9 lbs | 1.4 lbs |
| 2 ft | 0.131 gal | 0.49 L | 0.017 ft³ | 1.1 lbs | 1.8 lbs | 2.9 lbs |
| 5 ft | 0.327 gal | 1.24 L | 0.044 ft³ | 2.7 lbs | 4.4 lbs | 7.1 lbs |
| 10 ft | 0.653 gal | 2.47 L | 0.087 ft³ | 5.5 lbs | 8.8 lbs | 14.3 lbs |
| 20 ft | 1.306 gal | 4.94 L | 0.175 ft³ | 10.9 lbs | 17.7 lbs | 28.6 lbs |
| 50 ft | 3.26 gal | 12.4 L | 0.44 ft³ | 27.3 lbs | 44.2 lbs | 71.5 lbs |
| 100 ft | 6.53 gal | 24.7 L | 0.87 ft³ | 54.5 lbs | 88.4 lbs | 142.9 lbs |
| 250 ft | 16.32 gal | 61.8 L | 2.18 ft³ | 136.3 lbs | 221.0 lbs | 357.3 lbs |
| 500 ft | 32.65 gal | 123.6 L | 4.37 ft³ | 272.5 lbs | 442.0 lbs | 714.5 lbs |
Step-by-step mathematical demonstration using cylinder geometric principles and ASTM B88 specifications.
Nominal size is 1-1/4", but true inner diameter is 1.265 inches.
r = ID / 2 = 1.265 / 2 = 0.6325" Compute circular cross-section area using $A = \pi \times r^2$:
A = \pi \times (0.6325)^2 = 1.2568 sq in Multiply cross-sectional area by 12 inches (1 linear foot):
V_linear = 1.2568 \times 12 = 15.082 cu in/ft Divide cubic inches by 231 (cubic inches in 1 US Gallon):
Gallons/Ft = 15.082 / 231 = 0.0653 Gal/Ft Physical dimensions, pressure thresholds, and hydraulic velocity limits.
Primary Use Case: Used extensively in multi-unit residential buildings, commercial boiler headers, and heavy hydronic heating circuits.
Explore adjacent diameter calculations or compare with different copper types (Type K vs Type L).
Compare fluid holding capacity, wall thickness, and weight against other standard piping materials for 1-1/4" nominal diameter:
Frequently asked engineering and volumetric capacity questions for 1-1/4" copper tubing.
A 50-foot run of 1-1/4" Type L copper pipe holds 3.27 US Gallons (12.36 Liters) of water.