3 Phase Power Calculator
Calculate three-phase real power from line voltage, line current and power factor.
Interactive Electrical Calculator
3 Phase Power Calculator
Calculate three-phase real power from line voltage, line current and power factor.
Result
Enter values and calculate.
About the 3 Phase Power Calculator
Use the 3 Phase Power Calculator below to work through total power and load calculations across single-phase, three-phase and AC systems in seconds, right in your browser. Calculate three-phase real power from line voltage, line current and power factor. Power factor changes how much current a given load actually draws, so two loads with the same wattage can need very different conductor and breaker sizes.
It's aimed at electricians sizing panels and services, and engineers estimating total connected or demand load, who need a fast, reliable number without redoing the math by hand each time.
How the calculation works
Behind the scenes, the calculation follows:
P = √3 × V × I × PF.
Where each input maps to a field in the calculator above:
- Line Voltage in V.
- Line Current in A.
- Power Factor.
Change any field above and the result recalculates immediately — nothing is submitted anywhere, so it's safe to experiment freely.
A worked example
For example, start with 400 V for line voltage, 20 A for line current and 0.9 for power factor. Those defaults are only a starting point — replace them with your own measured or nameplate values, then press Calculate to get a result specific to your situation.
When to use the 3 Phase Power Calculator
Typical reasons people reach for the 3 Phase Power Calculator:
- Estimating total connected load for a new panel or service.
- Comparing single-phase and three-phase power for the same voltage and current.
- Checking a load calculation against a utility service size before requesting an upgrade.
- Sizing equipment for a workshop, small commercial space or off-grid system.
Good practice: Three-phase power calculations use √3 × V × I, not simply 3 × V × I, because of how the phases relate to each other.
Also worth knowing: Diversity and demand factors are usually applied on top of a simple connected-load sum for realistic panel and service sizing.
Frequently asked questions
What does the 3 Phase Power Calculator calculate?
Calculate three-phase real power from line voltage, line current and power factor.
Can I rely on this number for a real installation?
The formula above is applied exactly to the values you enter, so the math itself is precise. Real-world results can still differ due to component tolerances, temperature, installation method, equipment efficiency and local code requirements, so treat the output as a strong planning estimate and verify final designs against manufacturer data and the electrical code that applies to your installation.
Does this calculator store or send my data anywhere?
No. The 3 Phase Power Calculator runs entirely in your browser, and nothing you type is transmitted or stored anywhere.
What happens if I get this wrong?
Three-phase and single-phase power formulas differ by a √3 factor, and mixing them up is one of the most common load-calculation mistakes.
What should I do if the result looks off?
The 3 Phase Power Calculator works on any modern browser, phone or desktop, and recalculates as soon as you press Calculate. If a result looks off, double-check that every field is filled in with the unit shown next to it (mixing up units, such as W with kW, is the most common cause of an unexpected answer) and re-enter the values.