Enter the compression ratio and the atmospheric pressure into the calculator to determine the resulting pressure in bar. This calculator helps in understanding the pressure change due to compression in engines and other systems.

Compression Ratio to Bar Formula

The following formula is used to calculate the resulting pressure in bar.

P = CR * AP


  • P is the resulting pressure (bar)
  • CR is the compression ratio (dimensionless)
  • AP is the atmospheric pressure (bar)

To calculate the resulting pressure in bar, multiply the compression ratio by the atmospheric pressure.

What is Compression Ratio?

The compression ratio is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity. It is a critical parameter in engine design and performance, as it affects the engine’s efficiency and power output. A higher compression ratio typically means more power and better fuel efficiency, but it can also lead to increased engine knocking if not managed properly.

How to Calculate Resulting Pressure in Bar?

The following steps outline how to calculate the resulting pressure in bar.

  1. First, determine the compression ratio (CR).
  2. Next, determine the atmospheric pressure (AP) in bar.
  3. Next, gather the formula from above = P = CR * AP.
  4. Finally, calculate the resulting pressure (P) in bar.
  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.

Compression Ratio (CR) = 10:1

Atmospheric Pressure (AP) = 1 bar