Compute internal pipe capacity in metric Litres (L), Litres per metre (L/m), and cubic metres (m³) using millimetres and metres.
Calculations are based on cylindrical formula \(V = \pi r^2 L\). Verify dimensions against manufacturer specs for code submittals.
The Pipe Volume Calculator in Litres calculates internal fluid capacity in SI metric units (Litres, L/m, and m³) for standard ISO/EN and DIN cylindrical pipe systems.
Need US gallon or imperial capacity instead? Use our master Pipe Volume Calculator or the dedicated Pipe Volume Calculator in Gallons.
Follow these 4 simple steps to calculate litres in any metric pipe:
In the SI metric system, inside diameter is specified in millimetres (mm) and length in metres (m). The direct formula to output Litres is:
Volume (Litres) = (π × (ID in mm / 2)² × Length in metres) / 1,000 Where the mathematical variables represent:
ID / 2.| Metric Size (DN) | Inside ID (mm) | Litres / Metre (L/m) | Litres / 10 Metres | Water Weight / 10 m |
|---|---|---|---|---|
| DN 15 | 15 mm | 0.177 L/m | 1.77 L | 1.77 kg |
| DN 20 | 20 mm | 0.314 L/m | 3.14 L | 3.14 kg |
| DN 25 | 25 mm | 0.491 L/m | 4.91 L | 4.91 kg |
| DN 50 | 50 mm | 1.964 L/m | 19.64 L | 19.64 kg |
| DN 100 | 100 mm | 7.854 L/m | 78.54 L | 78.54 kg |
| DN 150 | 150 mm | 17.671 L/m | 176.71 L | 176.71 kg |
A mechanical engineer is designing a chilled water supply line with 25 metres of DN 50 copper pipe (inside diameter = 50 mm) and needs to verify fluid volume for glycol dosing.
Step-by-Step Metric Math:
r = 50 mm / 2 = 25 mm = 0.025 mA = π × (0.025)² = 0.0019635 m²V = 0.0019635 m² × 25 m = 0.049087 m³0.049087 m³ × 1,000 = 49.09 Litres49.09 L × 1.00 kg/L = 49.09 kgTo calculate pipe capacity in Litres, calculate cylinder volume in cubic metres (V = π × r² × L where r and L are in metres) and multiply by 1,000 (1 m³ = 1,000 Litres). Using millimetres: Volume (L) = (π × [ID in mm / 2]² × Length in metres) / 1,000.
A 50mm inside diameter pipe holds approximately 1.9635 litres of fluid per linear metre. A 10-metre run holds 19.64 Litres, and a 50-metre run holds 98.17 Litres.
In the metric system, 1 Litre of pure water weighs exactly 1 kilogram (1 kg = 2.2046 lbs). A pipe holding 50 Litres of water carries exactly 50 kg of water weight.
Divide the total litres by 1,000: Volume in m³ = Volume in Litres / 1,000. For example, 2,500 Litres equals 2.50 cubic metres.
DN stands for 'Diamètre Nominal' (Nominal Diameter). It is the European/ISO metric standard (EN 10255 / ISO 6708) designating pipe size (e.g., DN 25 ≈ 1 inch, DN 50 ≈ 2 inches, DN 100 ≈ 4 inches).
A 100mm inside diameter pipe has an internal area of 0.007854 m² and holds 7.854 litres of fluid per linear metre (78.54 Litres per 10 metres).