Calculating your real power is straightforward once you know the Three-Phase Power formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Three-Phase Power Calculator.
What is Three-Phase Power?
The Three-Phase Power calculation tells you your real power from a few simple inputs. The figure you are solving for here is the real power.
The Three-Phase Power formula
The core formula is:
Real power = √(3) × Line voltage × Line current × Power factor ÷ 1000Here is what each input means:
- Line voltage — a value measured in V. Example: 415 V.
- Line current — a value measured in A. Example: 10 A.
- Power factor — a number. Example: 0.8.
How to calculate it step by step
- Write down the line voltage (for example, 415 V).
- Write down the line current (for example, 10 A).
- Write down the power factor (for example, 0.8).
- Apply the formula above to get your real power.
- Double-check the result with the Three-Phase Power Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Line voltage | 415 V |
| Line current | 10 A |
| Power factor | 0.8 |
| Real power | 5.750 |
| Apparent power | 7.188 |
With line voltage of 415 V, line current of 10 A and power factor of 0.8, the real power works out to 5.750.
Example 2
With line voltage of 830 V, line current of 10 A and power factor of 0.8, the real power works out to 11.501.
| Result | Value |
|---|---|
| Real power | 11.501 |
| Apparent power | 14.376 |
Example 3
With line voltage of 210 V, line current of 10 A and power factor of 0.8, the real power works out to 2.910.
| Result | Value |
|---|---|
| Real power | 2.910 |
| Apparent power | 3.637 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Three-Phase Power Calculator does it instantly, for free, with the formula and a worked example built in.
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