Generator Pie 4+

Generator Calculations

Pork Pie Software Limited

Designed for iPhone

    • 4.6 • 5 Ratings
    • $3.99

iPhone Screenshots


Fuel, electric, acoustic and engine calculations in the palm of your hand! Includes supporting theory and worked examples. Knowledge is Power!

Generator calculations made easy!

As with all our Apps this App provides the underlying maths and theory behind the calculations together with worked examples. This will allow you to not just get an answer, but more more importantly, to understand how the answer was derived.

Generator Pie is written to allow you to undertake everyday three phase diesel generator calculations with ease. The following four features are available within the App:


This feature provides the following two generator sizing tools:

Estimate Size (Rule of Thumb): This options provides a method to approximate the required generator size based on the nature of the generator’s connected kW load and some basic assumptions.

ISO 8528 Rating Selector: This option allows the user to enter a generators Power Rating and Performance Class as defined by International Generator Standard ISO 8528. Upon entering Power Rating and Performance Class this feature then provides the corresponding performance criteria as defined by ISO 8528.


This feature provides the following four options:

Amps: Upon entering a generator’s kVA rating, with its line voltage and power factor a generators maximum running current (Amps) is calculated.

Short Circuit: Upon entering a generator’s kVA rating, line voltage, sub transient reactance (X’’d), transient reactance (X’d) and synchronous reactance (X’d) the generator’s corresponding short circuit currents are calculated.

kW to kVA: Upon entering a generator’s kW rating and power factor it’s kW rating is calculated.

kVA to kW: Upon entering a generator’s kVA rating and power factor it’s kW rating is calculated.


This feature provides the following four options:

Fuel Consumption: Upon entering a generator’s Prime kVA rating its fuel consumption is provided at 25%, 50%, 75% and 100% load.

Tank Estimator: By entering a generator’s 100% fuel consumption and desired running duration a fuel tank size is estimated.

Tank Sizing: This option allows all the physical parameters of a generators fuel tank to be entered together with the rate of fuel extraction. The app then calculates the tank’s effective and working capacities together with the generator’s maximum run time, normal run time, and reserve run time.


This feature allows you undertake basic generator noise attenuation calculations. The following two options are provided:

Distance to Given SPL: By entering a generator’s Sound Pressure Level (SPL) together with a lower SPL this feature calculates the distance necessary for the generator’s sound to be attenuated down to the lower SPL.

SPL at Given Distance: By entering a generator’s SPL together with a distance from the generator this feature calculates the SPL at the given distance from the generator.


This feature provides the following engine related tools:

Engine Speed: By entering the desired alternator electrical frequency and the number of poles on the alternator this feature calculates the engine speed required to achieve the desired output frequency in revolutions per minute (RPM).

Droop Speed Control: By entering the engine’s no load speed, typically its rated speed, and full load speed this feature calculates the percentage droop.

“Written by Engineers for Engineers”

About Pork Pie Software:

Pork Pie Software is a mobile app development company based in New Zealand. Our apps are actually written and coded by real engineers that practice in the engineering area that each app is written in.

All feedback and suggestions are genuinely welcome. As we write our own apps we can quickly update and improve our apps based on your feedback.

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What’s New

Version 4.0

Thanks for using our Generator Pie app. We’re constantly improving this app in conjunction with your feedback to make this app even better.

This update includes:

• New Litres to Gallons Conversion feature.
• Added Gallons option to all Fuel features.

If you like the app, please leave us a review!

“Written by Engineers for Engineers”

Ratings and Reviews

4.6 out of 5
5 Ratings

5 Ratings

App Privacy

The developer, Pork Pie Software Limited, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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