📉 Voltage Regulation Calculator
Calculate percentage voltage regulation from no-load and full-load voltage readings.
What this calculator does
Voltage regulation describes how much a transformer’s or power supply’s output voltage changes between having no load connected and being fully loaded. A lower percentage means a more stable, better-regulated output.
The formula
Percentage voltage regulation is calculated as %VR = ((Vnl − Vfl) / Vfl) × 100, where Vnl is the output voltage measured with no load connected, and Vfl is the output voltage measured under full rated load.
Well-designed power transformers typically have voltage regulation in the low single digits (often under 5%). This calculator is for general electrical education and equipment evaluation, not a substitute for manufacturer specifications or professional testing.