# Advice 1: How to calculate pipe diameter

If your goal is to calculate the diameter of the pipe, then it can be done using simple geometric calculations. Any pipe is a cylinder and has two diametera – external and internal, they differ by twice the wall thickness of the pipe. Payments can be made in different ways, depending on available data.
You will need
• Measuring tape
Instruction
1
In the most General case, the diameters pipe of wall thickness T can be calculated by measuring the circumference of its cross section. Let this length equal to L. Then, the formula for the circumference of a circle, its diameter will be equal to
d1 = L / N where L is the length of the circumferential section of the pipe, P = 3,14
Thus, D1 is the outer diameter.
2
The length of the inner diameterand pipe will be equal to
d2 = d1 – 2 * T, where T is the wall thickness of the pipe
3
If you have a piece of pipe and is known for its length and surface area, the diameters can be calculated using the formula of the area of the cylinder surface
d1 = P * h / S where h is a length of pipe, S is the surface area, P = 3,14
d2 = d1 – 2 * T, where T is the wall thickness of the pipe

# Advice 2 : How to calculate square pipe

Imagine that you are going to paint supplied to your home gas pipes. As you need to paint? One or two banks? As a rule, containers of paint, to write, to cover a square calculated is the amount of paint. So, in order to determine exactly how many cans of paint to take, you need to calculate the area of gas pipes.
You will need
• roulette;
• - caliper;
• - strong string;
• calculator.
Instruction
1
To calculate the area of a pipe of circular cross-section find out the length of the pipe in linear metres. Also, the calculation will need the outer diameter of the pipe.
2
Calculate the value of the outer diameter of the gas pipe. You can do it two ways. First method – measure the outer diameter of the gas pipe using a Vernier caliper. To do this, open the lips of this measuring tool and attach it to the pipe so that the pipe was between the jaws of the caliper. Then slide the sponge measuring tool: they should be tightly clasp the gas pipe. Looking at the measuring scale, determine the outer diameter of the pipe. The second method is grasp the tube thick thread. Then measure with tape measure the circumference of the pipe. Substituting value in the formula D = L / PI where L is the length of the circumference of the pipe, PI = 3,14 (PI), calculate the value of the outside diameter of the gas pipe. Translate the resulting figure is in meters.
3
Find the area of the gas pipe using the following formula: S = 2*PI*DMP*R, where PI is the number "PI" (3.14), DMP – gas length of pipe in linear meters, and R is the outer radius of the pipe. Given that the diameter is twice the radius, divide the result of the earlier calculations, the increased outer diameter in 2. Put all required data into the formula and calculate the area of the pipe.
Note
Count each measure several times! One mistake will have a significant impact on the final result.