Transformer Turns Ratio Calculator
Fill in the values and the answer updates as you type.
How the Transformer Turns Ratio Calculator works
Secondary voltage = primary voltage × secondary turns ÷ primary turns. Primary current = secondary power ÷ efficiency ÷ primary voltage, since a real transformer draws more power than it delivers. Example: with the default values, secondary voltage comes to 23 V.
Inputs and results
The Transformer Turns Ratio Calculator takes 5 inputs and gives 4 results.
What you enter
- Primary voltage (V) — starts at 230.
- Primary turns — starts at 1000.
- Secondary turns — starts at 100.
- Secondary load current (A) — starts at 5.
- Transformer efficiency (%) — starts at 95.
What you get
- Secondary voltage (V)
- Turns ratio (primary:secondary)
- Secondary power (VA)
- Primary current (A)
Example: Transformer Turns Ratio Calculator with the starting values
With primary voltage 230 V, primary turns 1000, secondary turns 100, secondary load current 5 A and transformer efficiency 95 %, the calculator returns:
| Secondary voltage (V) | 23 |
|---|---|
| Turns ratio (primary:secondary) | 10 |
| Secondary power (VA) | 115 |
| Primary current (A) | 0.5263 |
Change any value above and the results update straight away.
Transformer Turns Ratio Calculator FAQ
How do I use the Transformer Turns Ratio Calculator?
Enter primary voltage, primary turns, secondary turns and secondary load current in the fields, then read secondary voltage (v), turns ratio (primary:secondary), secondary power (va) and primary current (a) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Transformer Turns Ratio Calculator calculate?
Secondary voltage and currents from a transformer turns ratio. It returns secondary voltage (v), turns ratio (primary:secondary), secondary power (va) and primary current (a) from the 5 values you provide.
What values does the Transformer Turns Ratio Calculator start with?
It opens with primary voltage 230 V, primary turns 1000, secondary turns 100 and secondary load current 5 A so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Transformer Turns Ratio Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Transformer Turns Ratio Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.