Enter the acceleration due to gravity and the vertical distance between the liquid surface and the outlet into the calculator to determine the speed of the outflow.

Torricelli’s Law Formula

The following formula is used to calculate the speed of fluid flowing out of an orifice under the force of gravity according to Torricelli’s Law.

v = √(2gh)

Variables:

  • v is the speed of the outflow (m/s)
  • g is the acceleration due to gravity (m/s²)
  • h is the vertical distance between the liquid surface and the outlet (m)

To calculate the speed of the outflow, multiply the acceleration due to gravity by 2, then multiply the result by the vertical distance between the liquid surface and the outlet. Take the square root of the result to get the speed of the outflow.

What is a Torricelli’s Law?

Torricelli’s Law is a principle in fluid dynamics that describes the speed of fluid flowing out of an orifice under the force of gravity. It states that the speed (v) of the outflow is proportional to the square root of the vertical distance (h) between the liquid surface and the outlet, or v = √(2gh), where g is the acceleration due to gravity. This law is essentially a specific application of Bernoulli’s principle, and is named after the Italian scientist Evangelista Torricelli.

How to Calculate Torricelli’s Law?

The following steps outline how to calculate the speed of the outflow using Torricelli’s Law.


  1. First, determine the value of acceleration due to gravity (g) in meters per second squared (m/s²).
  2. Next, determine the vertical distance between the liquid surface and the outlet (h) in meters (m).
  3. Next, gather the formula from above: v = √(2gh).
  4. Finally, calculate the speed of the outflow (v) using the formula.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

acceleration due to gravity (g) = 9.8 m/s²

vertical distance (h) = 5 m