Velocidade de Torricelli
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
v = √(2gh)
About this calculator
The Torricelli Velocity Calculator determines the speed of a fluid flowing through an orifice under gravity, based on Torricelli's Theorem. The formula v = √(2gh) relates velocity (v) to gravitational acceleration (g) and the height of the fluid column (h) above the orifice. It is a direct application of energy conservation, ignoring friction losses.
How it works: the user inputs the height of the fluid column (in meters) and the calculator uses g = 9.81 m/s² to compute the theoretical exit velocity. For example, for a height of 1 meter, the velocity is approximately 4.43 m/s. The result is given in meters per second.
When to use: designing drainage systems, calculating flow from tanks, sizing spillways, or in hydraulics and basic physics problems. It is useful for engineers, students, and professionals working with fluids.
Cautions: the formula assumes an ideal fluid (no viscosity) and a small orifice relative to the tank. In practice, there are losses due to friction and jet contraction (discharge coefficient). Use corrected values for greater accuracy in real applications.
Frequently asked questions
Does Torricelli's formula work for any liquid?
Yes, as long as the liquid is considered ideal (no viscosity). In practice, more viscous liquids have lower velocities due to friction.
What is the unit of velocity?
Velocity is calculated in meters per second (m/s), since height is provided in meters and gravity in m/s².
Do I need to consider atmospheric pressure?
Torricelli's formula already accounts for atmospheric pressure acting equally on the liquid surface and the orifice outlet, so no additional adjustment is needed.
Is the result accurate for real projects?
Not exact, because the formula ignores friction losses and jet contraction. For greater accuracy, multiply the result by the discharge coefficient (typically between 0.6 and 0.98).
Can I use it to calculate flow rate?
Yes, by multiplying the velocity by the orifice area. But remember that the actual flow rate will be lower due to the discharge coefficient.