Transformer Turns Ratio
Calculator
Results
- Turns ratio
- 10
- Secondary voltage (V)
- 23
- Secondary current (A)
- 20
- Apparent power (VA)
- 460
Electrical results
| Turns ratio | 10 |
| Secondary voltage (V) | 23 |
| Secondary current (A) | 20 |
| Apparent power (VA) | 460 |
formula-map diagram
- Turns ratio
- 10
- Secondary voltage (V)
- 23
- Secondary current (A)
- 20
- Apparent power (VA)
- 460
Electrical relationship
Formula
Vp / Vs = Np / Ns= 10
Note
This is a simplified model: it applies the textbook relationship to the numbers you entered and assumes ideal components, steady-state sinusoidal conditions, balanced loads and copper resistivity of 0.0172 Ω·mm²/m at 20 °C. It ignores component tolerances, temperature drift, skin effect, harmonics, inrush, transformer and battery losses, and it is not a substitute for the wiring code that applies where you are. Have any installation sized and verified by a licensed electrician or engineer.
More in Electrical engineering
See all →Frequently asked questions
What does the turns ratio of a transformer tell you?+
The turns ratio (N1:N2) equals the ratio of primary to secondary voltage: Vp/Vs = Np/Ns. A step-down transformer has more primary turns than secondary, and a step-up transformer has fewer.
How does the turns ratio affect current, not just voltage?+
Current changes inversely to voltage across a transformer: Ip/Is = Ns/Np. So a transformer that steps voltage down by a factor of 10 steps current up by that same factor, assuming an ideal, lossless transformer.
Why is transformer power (roughly) the same on both sides?+
An ideal transformer doesn't generate or consume power, it just transforms voltage and current — so primary power (Vp x Ip) equals secondary power (Vs x Is), with real transformers losing a small percentage to core and winding losses.
Does the turns ratio depend on the power rating of the transformer?+
No, the turns ratio is purely a function of voltage transformation, set by how the windings are constructed. The power rating (VA or kVA) is a separate specification determined by wire gauge and core size, which limits how much current the transformer can safely handle.
Can a transformer's turns ratio be used with AC only, or DC too?+
Transformers only work with AC, because the turns ratio relationship depends on a changing magnetic flux induced by alternating current; a steady DC current produces no changing flux and therefore no voltage transformation.