Bernoulli equation is the most important equation for engineering analysis of flow problems. Most practical tasks are resolved by direct implementation of Bernoulli equation with its corresponding condition - continuity equation. The importance of the equation is the result of its content, which represents balance of certain fluid energy characteristics.

Every single member, in Bernoulli equation on the left side of the above equation, represents certain energy contained in the unit of mass in the fluid stream. The first member is pressure energy, the second one is kinetic energy and the third one is potential energy. The constant on the right side of the above equation means that the sum of all three members is constant for any point in fluid stream.

This behavior is actually Bernoulli's principle that states that when flow velocity is increased pressure or potential energy will decrease. This principle is only valid for inviscid flow and non-conducting fluid. Bernoulli's principle is widely used like in wing design where the shape of wing makes flow velocity change and as a result, pressure difference is created on the upper and bottom surface area of the wing, resulting in the force pointing up for airplanes (lifting up the plane) or down for racing cars (adding to the gravity in additional down force for better grip).

With this Bernoulli's equation calculator you can calculate stream parameters, pressure, velocity, height and diameter in any point for known ones in some other point. The point of stream line where stream parameters are known is marked as position one (left side of the calculator) and the point in which you want to calculate stream parameters is marked as two (right side of the calculator). Parameters in point two that you can calculate are:

- Pressure
- Flow velocity
- Stream diameter
- Height (position)

In Selection section you can select values to calculate. Not selected values should be entered by yourself. If you select to use volume flow rate in calculations, you can select to calculate between:

- Flow velocity at the start of stream
- Flow diameter at the start of stream
- Volume flow rate

In Report section you have instant calculation report for input values. From there you can copy/paste report to your text editor.

- Calculate how stream properties will change when flow conditions are changing
- Calculate how pressure will change when fluid flows through pipes with different internal diameters
- Calculate how pressure will change when flowing fluid changes its elevation
- Calculation of volume or mass flow rate for given fluid density

- p
_{1}– pressure in position one - Static pressure of fluid in the point in which flow parameters are known – referent position
- p
_{2}– pressure in position two - Static pressure of fluid in the point in which flow parameters should be calculated
- D
_{1}- diameter in position one - Internal pipe or stream diameter in the point in which flow parameters are known
- D
_{2}- diameter in position two - Internal pipe or stream diameter in the point in which flow parameters should be calculated
- V
_{1}- velocity in position one - Flow velocity where flow diameter is D1 and where flow parameters are known
- V
_{2}- velocity in position two - Flow velocity where flow diameter is D2 and where flow parameters should be calculated
- z
_{1}– height in position one - Height or elevation of the fluid stream in the point in which flow parameters are known
- z
_{2}– height in position two - Height or elevation of the fluid stream in the point in which flow parameters should be calculated
- q - volumetric flow rate
- Fluid flow rate in terms of units of volume per unit of time. Considered to be constant
- ṁ - mass flow rate
- Fluid flow rate in terms of units of mass per unit of time. Considered to be constant
- ρ - fluid inlet density
- Density of fluid in terms of mass per unit of volume. Considered to be constant
- p
_{1}- p_{2}- pressure drop - Pressure difference between two points of stream line

- Related links, references:
- Read more on Bernoulli's principle
- Read more on Continuity equation
- Find more about Daniel Bernoulli, prominent mathematicians on Wikipedia.