Calculate velocity, Reynolds number, friction factor, head loss, and pressure drop for pipe flow. Includes elevation change and pumping power.
Pipe flow analysis is the bread and butter of hydraulic engineering. Given a pipe geometry, fluid properties, and flow rate, this calculator determines velocity, Reynolds number, friction factor (via the Colebrook–White equation), head loss, and pressure drop. It also accounts for elevation changes and computes the pumping power required.
Selecting the right pipe diameter is a balance between cost and energy: smaller pipes are cheaper but produce higher velocities and pressure drops; larger pipes reduce friction but cost more. The diameter comparison table lets you evaluate multiple sizes at once to find the optimum. Typical design velocities for water are 1–3 m/s; for air in ducts, 5–15 m/s.
Flow rate inputs accept liters per second, liters per minute, US gallons per minute, or cubic meters per second. With preset pipe sizes from DN15 to DN300 and common fluids, you can run a piping analysis in seconds. Use this as a practical reminder before finalizing the result.
Pipe flow calculations are essential for plumbing design, HVAC, industrial process piping, fire protection, and irrigation. This tool combines velocity, friction, elevation, and power analysis in one interface with common pipe-size presets. The note above highlights common interpretation risks for this workflow. Use this guidance when comparing outputs across similar calculators. Keep this check aligned with your reporting standard.
Velocity: V = Q / A = Q / (π D²/4) Reynolds: Re = ρVD / μ Friction: Colebrook–White equation Head loss: h_L = f (L/D) V²/(2g) Pressure drop: ΔP = ΔP_friction + ρgΔz Pumping power: P = ΔP × Q
Result: V = 0.61 m/s, ΔP ≈ 1.8 kPa
A = π/4 × 0.102² = 8.17×10⁻³ m². V = 0.005/0.00817 = 0.61 m/s. Re ≈ 60 800, f ≈ 0.021. ΔP = 0.021 × (100/0.102) × 998 × 0.61²/2 ≈ 1 800 Pa.
Use consistent units, verify assumptions, and document conversion standards for repeatable outcomes.
Most mistakes come from mixed standards, rounding too early, or misread labels. Recheck final values before use. ## Practical Notes
Use this for repeatability, keep assumptions explicit. ## Practical Notes
Track units and conversion paths before applying the result. ## Practical Notes
Use this note as a quick practical validation checkpoint. ## Practical Notes
Keep this guidance aligned to the calculator’s expected inputs. ## Practical Notes
Use as a sanity check against edge-case outputs. ## Practical Notes
Capture likely mistakes before publishing this value. ## Practical Notes
Document expected ranges when sharing results.
Residential water systems: 0.5–1.5 m/s. Commercial: 1–3 m/s. Industrial: up to 5 m/s. Higher velocities increase erosion rate and noise.
Pressure drop is roughly proportional to 1/D⁵ for turbulent flow. Doubling the diameter reduces friction loss by about 97%.
Yes. Each elbow, valve, or tee contributes a minor loss ΔP = K ρV²/2. For long straight runs, minor losses are small; for compact piping with many fittings, they can dominate.
When fluid flows uphill, gravitational potential energy increases, requiring additional pressure: ΔP_elev = ρg Δz. A 10 m rise in water adds ≈ 98 kPa.
1 L/s = 60 L/min = 15.85 gpm = 0.001 m³/s. This calculator handles the conversion automatically.
Pumping power P = ΔP × Q is the hydraulic power. The motor power is higher because pump efficiency is typically 60–85%. Divide hydraulic power by efficiency to get motor power.