When to use this calculator
A lower secondary-to-primary turns ratio reduces voltage in an ideal transformer.
Explore the dc circuits & components calculators for other questions in this topic. For a related calculation, use the Voltage Divider Calculator: Estimate unloaded output voltage from a two-resistor divider.
PUTTING IT INTO PRACTICE
Transformer Voltage: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Primary voltage (V) | 240 |
| Primary turns (integer) | 1,000 |
| Secondary turns (integer) | 100 |
| Result | 24 V |
- Check the input labels and enter the example values above.
- Apply the relationship: Secondary voltage = primary voltage × secondary turns/primary turns.
- The result is 24 V, rounded for display.
How to interpret your result
Ideal AC transformer model; losses, regulation and saturation are excluded.
Ideal component models omit tolerances, heat and parasitic effects. Distinguish nominal energy from usable energy for batteries. Component ratings and installation requirements need separate manufacturer and design checks.
Frequently asked questions
Can these calculations select a safe installation rating?
No. They explain ideal relationships and do not include every thermal, protective or regulatory requirement.
When is the transformer voltage calculator useful?
A lower secondary-to-primary turns ratio reduces voltage in an ideal transformer.
How do I use the transformer voltage calculator?
Enter primary voltage (v), primary turns (integer), secondary turns (integer). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Secondary voltage = primary voltage × secondary turns/primary turns.
What should I check before using the result?
Ideal AC transformer model; losses, regulation and saturation are excluded.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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