Venturi Meter Calculator
Flow through a venturi follows from Bernoulli and continuity: a 200 × 100 mm venturi on water with a 250 mm mercury reading passes Q = 62.4935 L/s.
≈ 0.98 for a venturi, 0.61–0.65 for a sharp-edged orifice.
62.4935358167987 L/s
Full answer, then cut to fewer decimals (not rounded):
- 62.4935358167987 L/s
- 62.493535816798 L/s
- 62.49353581679 L/s
- 62.4935358167 L/s
- 62.493535816 L/s
- 62.49353581 L/s
- 62.4935358 L/s
- 62.493535 L/s
- 62.49353 L/s
- 62.4935 L/s
- 62.493 L/s
- 62.49 L/s
- 62.4 L/s
- Actual discharge
- 0.0624935 m³/s
- Theoretical discharge
- 63.7689 L/s
- Differential head h
- 3.15 m of fluid
- Velocity at the throat
- 7.95692 m/s
- Diameter ratio β = d₂/d₁
- 0.5
Step-by-step solution
- h = x (Sm/S − 1) = 0.25 × (13.6 ÷ 1 − 1) = 3.15 m
- Q = Cd A₁A₂√(2gh) ÷ √(A₁² − A₂²)
- = 0.98 × 0.0314159 × 0.00785398 × 7.86149 ÷ 0.0304183 = 0.0624935 m³/s
Venturi Meter Formula
Q = Cd A₁A₂√(2gh) ÷ √(A₁² − A₂²)
h = x(Sm/S − 1) for a manometer, or Δp/ρg
Worked Example
A 200 × 100 mm venturi on water with a 250 mm mercury manometer reading:
- h = x (Sm/S − 1) = 0.25 × (13.6 ÷ 1 − 1) = 3.15 m
- Q = Cd A₁A₂√(2gh) ÷ √(A₁² − A₂²)
- = 0.98 × 0.0314159 × 0.00785398 × 7.86149 ÷ 0.0304183 = 0.0624935 m³/s
Theoretical discharge: 63.7689 L/s · Differential head h: 3.15 m of fluid · Velocity at the throat: 7.95692 m/s · Diameter ratio β = d₂/d₁: 0.5
More Fluid Mechanics Calculators
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Example: Water at 200 kPa and 2 m/s accelerating to 6 m/s while rising 3 m: Pressure at 2, p₂ = 154.57 kPa.
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Hydrostatic Force Calculator
F = ρ g A h̄, h* = h̄ + IG sin²θ / (A h̄)
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Example: A vertical 2 m wide, 3 m high gate with its top edge 1 m below water: Total pressure force F = 147.15 kN.
-
Metacentric Height Calculator
GM = BM − BG = I/V − BG
I second moment of the waterplane, V displaced volume, BG distance from B to G
Example: A 4 m × 2 m × 1 m block with specific gravity 0.6 floating in water: Metacentric height GM = 0.355556 m.
Frequently asked questions
How do I convert a manometer reading to head?
h = x(Sm/S − 1) in metres of the flowing fluid: 250 mm of mercury under water is 0.25 × 12.6 = 3.15 m.
Why is Cd lower for an orifice than a venturi?
The jet contracts to a vena contracta and loses energy in eddies, so Cd ≈ 0.62 instead of about 0.98.
Sources
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Venturi Meter Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/venturi-meter-calculator/
IEEE
Scientific Converters, "Venturi Meter Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/venturi-meter-calculator/