Transformer Sizing Calculator
The Transformer Sizing Calculator picks the standard kVA rating for a load with spare capacity and reports the resulting loading. Example: for a 100 kVA load on a 13.8 kV / 400 V 3-phase supply with 25% spare, Rated size = 150 kVA, Required = 125 kVA, Loading = 66.7 % (per PEC 2017 Art. 4.50 | IEC 60076-1:2011).
How it works
Computed from your inputs per PEC 2017 Art. 4.50 | IEC 60076-1:2011.
Worked example (Electrical & Power)
Inputs: a 100 kVA load on a 13.8 kV / 400 V 3-phase supply with 25% spare.
| Result | Value |
|---|---|
| Rated size | 150 kVA |
| Required | 125 kVA |
| Loading | 66.7 % |
Computed live by WorkHive's calculation engine; standard: PEC 2017 Art. 4.50 | IEC 60076-1:2011.
How to use this calculator
- Enter the figures for the duty you are sizing: the worked example below uses a 100 kVA load on a 13.8 kV / 400 V 3-phase supply with 25% spare.
- The calculator returns Rated size, Required, Loading, computed per PEC 2017 Art. 4.50 | IEC 60076-1:2011.
- Check the worked example to confirm the method matches how you would do it by hand, then run your own numbers in the interactive tool.
FAQ
What is a transformer sizing calculator kVA?
The Transformer Sizing Calculator is a free online tool that computes picks the standard kVA rating for a load with spare capacity and reports the resulting loading. It shows the formula and a fully worked example so you can check the method, not just the number.
How is it calculated?
The result is computed from your inputs following PEC 2017 Art. 4.50 | IEC 60076-1:2011. The worked example on this page shows a real computation with real numbers.
Is the calculator free?
Yes. WorkHive's engineering calculators are free to use, no sign-up needed for the tools. WorkHive is a free, offline-first maintenance platform built for Philippine industrial plants.
Run it on your own numbers
Open the interactive Transformer Sizing Calculator in WorkHive: free, no sign-up needed for the calculators.