# Transformer Sizing Calculator

Our transformer size calculator can **find the right transformer size (single or three-phase) for any load you require!**

Within this short text, you will learn:

- The
**working principle**of transformers; - How to size a
**single-phase transformer**; - How to calculate transformer size for a
**three-phase transformer**; and **More!**

Keep reading to learn about all the features of this **transformer kVA calculator**.

## How do transformers work?

Transformers are electrical devices that *transform* voltages. They can bring the voltage **up** or **down** depending on their purpose.

Transformers work in the following way:

- Alternating current (
**AC**) flows through a coil of wire, producing a*changing magnetic field.* - A
**magnetic core**leads this magnetic flux through another coil of wire which has a*different number of turns*than our first coil. - Electromagnetic induction produces an
**electromotive force**, a voltage difference, on the second coil. - According to the number of turns, this transformer will create a
**step-up**or**step-down**in voltage.

## How to size a transformer

We size transformers based on the load they should power and use **kVA**, kilo volt-ampere, to rate them (what is kVA?). *A higher transformer's kVA means a higher current and voltage output.*

To find the appropriate size for our load, we need two things:

- $I$, the
**current**of our load; and - $V$ our load's
**voltage**requirement.

Then, all we need to do is plug these parameters into the respective transformer formula.

For a **single-phase transformer**, we have:

and for a **three-phase transformer**:

🙋 This transformer sizing calculator operates with both equations: it works as a **single-phase transformer kVA calculator** *and* as a **3-phase transformer calculator!** Simply select the transformer type at the top of this tool and type in your parameters.

## How to use our transformer sizing calculator

Using this tool is straightforward:

- Select the
**type of transformer**(single or three-phase). - Input your
**load's current**requirement. - Input your
**load's voltage**requirement. - Our calculator will automatically output the
**minimum kVA rating**for the transformer.**Give it a try!**