Enter the number of turns in secondary, the number of turns in primary, and the voltage in primary (volts) into the calculator to determine the Step Down Voltage. 

Step Down Voltage Formula

The following formula is used to calculate the Step Down Voltage.

SDV = Ns/Np * Vp
  • Where SDV is the Step Down Voltage (volts)
  • Ns is the number of turns in secondary 
  • Np is the number of turns in primary 
  • Vp is the voltage in primary (volts) 

To calculate the step down voltage, divide the number of turns in the secondary by the number of turns in the primary, then multiply by the primary voltage.

How to Calculate Step Down Voltage?

The following example problems outline how to calculate Step Down Voltage.

Example Problem #1

  1. First, determine the number of turns in secondary. In this example, the number of turns in secondary is determined to be 34 .
  2. Next, determine the number of turns in primary. For this problem, the number of turns in primary is measured to be 14 .
  3. Next, determine the voltage in primary (volts). In this case, the voltage in primary (volts) is found to be 23.
  4. Finally, calculate the Step Down Voltage using the formula above: 

SDV = Ns/Np * Vp

Inserting the values from above and solving the equation yields: 

SDV = 34/14 * 23 = 55.85 (volts)


Example Problem #2

Using the same method as above, determine the variables required by the equation. For this example problem, these are:

number of turns in secondary = 3

number of turns in primary = 6

voltage in primary (volts) = 200

Enter these given values into the calculator or above yields: 

SDV = 3/6 * 200= 100 (volts)