In the 21st century, scientists are doing some ground-breaking work. These ground-breaking works are accumulative works of numerous experiments and calculations. These experiments and calculations are based on a lot of conditions and constants. To get the right value of these constants, it is very important to do the calculations precisely and that can only be done using a calculator. For example, a Dynamic Viscosity Calculator to calculate the value of dynamic viscosity. So, here we will be discussing some physical quantities that can be calculated using formulas as well as calculators. Pressure Drop: In a pipeline, pressure drop can occur due to rough surface, turbulence, elevation change, friction inside the pipe, and many other factors. The common process to calculate pressure drop or head loss is the Darcy-Weisbach equations. The pressure drop is denoted by J. It depends on the diameter of the pipe D, gravity g, friction factor f, length of the pipe l, and velocity of