# How To Calculate Amplitude Modulation

Amplitude modulation, commonly known as AM, is a type of signal transmission which is used in many radios for broadcasting signals. In amplitude modulation, the amplitude of the sound waves is varied to transmit the signals, as opposed to other types of signal transmission such as FM, where the frequency of the sound waves are changed or modulated in order to transmit signals. If you want to calculate the amplitude modulation for a given sound signal, you will need to know the modulation index. Here’s how you can follow through with the calculation.

**Get the formula**. To solve for the amplitude modulation of a given sound wave, you should first known the formula. There are plenty of text books in physics that will give you the formula, although you can also do your own research on the web to solve for the amplitude modulation formula. The formula is generally used to calculate the amplitude modulation is the modulation index, which will give you the quantity of how much the signals have been changed from their original state in the process of amplitude modulation. The formula is h= (peak value of m (t))/ (A) =M/A

**Get the values**. Once you know the values, the next step is to figure out the figures used in the equation. The values that you will need are the amplitude, the modulation value, and the t or the time. Usually you will need to use precise amplitude graphing equipment to test the modulation levels and the amplitude levels to be used for the equation. If you are solving for the amplitude modulation for class, however, these values are usually provided as givens in the equation problem. Usually, the amplitude will be provided in a graph, which starts from negative 2 to positive two. The length between the troughs and crests in the graph will indicate the percentage of modulation.

**Solving**. Once you have the values for the different variables to be used for solving for the amplitude modulation, the next step is to substitute the values in the equation. In substitution, you will simply replace the characters in the equation with the actual values derived from your tests or given in the problems. Once the substation has been carried out, proceed to solving as usual. As rule, you should follow the basics of MDAS, which means that you should solve multiply first, then divide, add, and subtract – whenever called for in the equation. All the sub-equations in the amplitude index equation which are inside a parenthesis should also be solved first, before the sub-equations outside of the parenthesis.

**Interpreting your results**. Once you have finished solving or the value of h, or the value of the modulation depth, you will know how much amplitude modulation has occurred from the original sound wave. You can then modify sound wave in order to make it clearer or more powerful for sound transmission in broadcasting.

Calculating for the amplitude modulation may seem challenging at first. But with practice and the correct formula, solving for AM equations and AM problems should be easy.