Transformer Voltage Calculator

Easily calculate transformer output voltage using turns ratio or input voltage. Includes formulas, conversion tables, worked examples, and FAQs for quick reference.

primary to secondary voltage converter

Transformer voltage can be computed using the formula of turns ratio: V s = V p x (N s/ N p). In this case, V p is the primary voltage, N s is the secondary turns, and N p is the primary turns. The converse form of the formula can also be used to obtain input voltage when the output is known.

Formula & Table Summary:

Secondary voltage: V_s = V_p × (N_s / N_p)
Primary voltage: V_p = V_s × (N_p / N_s)
Turns ratio from voltages: N_p/N_s = V_p/V_s
Percentage step (approx): %change = (V_s − V_p)/V_p × 100%

Converter Table (Input → Output)

Input	Formula / Step	Output
V_p, N_p, N_s	V_s = V_p × (N_s/N_p)	Secondary voltage V_s
V_s, N_p, N_s	V_p = V_s × (N_p/N_s)	Primary voltage V_p
V_p, V_s	Turns ratio = V_p/V_s	N_p/N_s (ratio)
Desired V_s, V_p	Choose N_s/N_p = V_s/V_p, round to manufacturable turns	Recommended turns ratio

electrical transformer voltage tool

The transformer voltage calculator can be used to find the secondary (output) or the primary (input) voltage of a transformer in a small amount of time using its turns ratio. The simple correlation is calculated as per the formula as V p/V s= N p/N s where V p and V s denote the primary and secondary voltage, and N p and N s denote the number of turns on the primary and secondary windings. When there are more turns in the secondary, the transformer increases or when there are less in the secondary, it decreases voltage. It comes in handy particularly in the design and analysis of power supplies, electrical circuits, and motor control systems. The ability to instantly change input to output voltages saves time and eliminates manual calculation errors by engineers, technicians and students with a calculator.

calculate transformer output voltage

Scenario	Inputs	Calculation	Result
Step-down	V_p=230 V, N_p=1000, N_s=100	V_s=230×(100/1000)	V_s=23.0 V
Step-up	V_p=12 V, N_p=50, N_s=500	V_s=12×(500/50)	V_s=120 V
Find primary	V_s=24 V, N_p=200, N_s=100	V_p=24×(200/100)	V_p=48.0 V
Turns ratio from volts	V_p=120 V, V_s=12 V	Np/Ns = 120/12	Turns ratio = 10 : 1

Frequently Asked Questions - Transformer Voltage Calculator:

How do you calculate transformer secondary voltage?

Use Vs = Vp × (Ns/Np), where Vs is secondary voltage, Vp is primary voltage.

How do you calculate transformer primary voltage?

Use Vp = Vs × (Np/Ns), rearranging the turns ratio formula.

What is the transformer turns ratio formula?

Vp/Vs = Np/Ns, where Np and Ns are the number of turns on primary and secondary windings.

What happens if Ns > Np?

The transformer steps up voltage (increases output).

What happens if Ns < Np?

The transformer steps down voltage (reduces output).

Can I calculate turns ratio from voltages?

Yes, turns ratio Np/Ns = Vp/Vs.

Why is turns ratio important?

It determines whether the transformer steps voltage up or down.

Is frequency considered in transformer voltage calculations?

Basic voltage ratio formulas assume constant frequency.

What are typical applications of step-down transformers?

Used in power supplies to convert mains voltage to low voltage.

What is the efficiency assumption in basic voltage calculations?

They assume an ideal transformer with negligible losses.

Tags: transformer voltage calculator turns ratio to voltage formula primary to secondary voltage converter voltage step up step down calculator transformer turns ratio equation ac transformer calculator electrical transformer voltage tool input to output voltage calculator voltage ratio transformer calc calculate transformer output voltage

Transformer Voltage Calculator | Turns Ratio & Output Voltage