Transformer Ratio Calculator

Calculate transformer ratios for electrical engineering projects.

What this calculator does

Vp/Vs = Np/Ns (turns ratio equals voltage ratio).

How it works

Ideal transformer: Pin = Pout (power is conserved).

When to use this calculator

This tool is most useful when working from known parameters toward an unknown output — the standard direction of engineering calculation. Enter measured or specified values to get the derived result.

Common mistakes

Many engineering errors stem from applying a formula outside its valid range. Most standard engineering formulas have boundary conditions — material limits, temperature ranges, or loading assumptions — that must be satisfied for the result to be reliable.

Real-world scenarios

An engineer compares two design options with different material grades. Running both through the relevant strength or stiffness calculation reveals which option meets the performance specification with an adequate safety factor, informing the material selection decision.

Frequently asked questions

What is a turns ratio?

The ratio of primary to secondary coil windings. Np:Ns = Vp:Vs.

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