PCP Air Efficiency Calculator

To use the calculator:
  1. record the starting pressure of your gun
  2. shoot a string of shots thru the chrony
  3. record the ending pressure and the average fps shown by the chrony
Enter all the form fields without commas and click Calculate to learn the efficiency of your gun in bar-cc/FPE and in FPE/cuin. The results screen gives you an option to print all the data for your records.
PSI before first shot

Enter an integer from 1000 to 5000
PSI after last shot

Enter an integer from 200 to 5000 which is less than the first PSI
Gun tank volume in cc

Enter an integer from 1 to 20000
Pellet weight

Enter an integer or decimal number from 2.1 to 1000
Total number of shots

Enter an integer from 1 to 500
Average FPS for all the shots

Enter an integer from 100 to 1500

Want to keep some of your previous data? Don't clear.
Just change the other fields and click Calculate again.

Typical PCP Performance

(These ranges are no more than a starting point.)

  Low Power Moderate Power High Power Maximum Power
Efficiencyexcellentgoodfairvery low
FPE/cuin1.4 to 2.01.0 to 1.40.7 to 1.00.7-
Bar-cc/FPE8 to 1212 to 1616 to 2525+
Shot Counthighmediumlowvery low
Examples10m targetstock small caliberstock big boremodded big bore

Algorithms courtesy of Lloyd Sikes. » E-mail Lloyd
Website and programming by Mary Ellen Sikes.

Practical science for the airgun community
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