3 Phase Motor Torque Calculator

A motor turns power into motion. Torque tells you how hard it can turn.

Our 3 phase motor torque calculator makes this job fast. You can find torque from motor power and speed. You can also use voltage, current, power factor, and motor efficiency.

This tool helps with motor checks to prevent motor overload, load work, and basic motor design. It can help you with electric motor sizing before you pick a drive or load.

You don't need to do long math by hand. Just enter the right values and let the tool do the work.

3 Phase Motor Torque Formula

The main 3 phase motor torque formula is:

Torque = (9550 × Power in kW) ÷ Speed in RPM

Here:

Power means motor output power in kW.

Speed means motor speed in RPM.

Torque comes out in N·m.

For example, a 15 kW motor runs at 1,480 RPM.

Torque = (9550 × 15) ÷ 1480

Torque = 96.79 N·m

So, the motor gives about 96.79 N·m of shaft torque.

This is the best formula when you know the motor's real output power.

Electrical 3 Phase Motor Torque Formula

You can also find torque from motor electrical data.

First, find three phase input power:

Input Power = √3 × Voltage × Current × Power Factor

Then find motor output power:

Output Power = Input Power × Efficiency

Next, use:

Torque = (9550 × Output Power in kW) ÷ Speed in RPM

So, the full 3 phase AC motor torque formula is:

Torque = (9550 × √3 × Voltage × Current × Power Factor × Efficiency) ÷ (1000 × RPM)

Use efficiency as a decimal. For example, 90% becomes 0.90.

This method works well when you know the motor's electrical data.

How to Use Online 3 Phase Motor Torque Calculator

1. Choose the power method or electrical method.
2. Enter motor power and speed for the power method.
3. Or enter voltage, current, power factor, efficiency, and speed.
4. Check each value before you click the calculate button.
5. Read the torque result in N·m.

That's it. The calculator does the math for you.

Example 3 Phase Motor Torque Calculation

Let's use a simple motor example.

The motor has 400 V line voltage. It draws 15 A. Its power factor is 0.85. Its efficiency is 90%. The speed is 1,450 RPM.

First, find input power:

Input Power = 1.732 × 400 × 15 × 0.85

Input Power = 8,833.46 W

Now find output power:

Output Power = 8,833.46 × 0.90

Output Power = 7,950.11 W

Convert watts to kW:

Output Power = 7.95 kW

Now find torque:

Torque = (9550 × 7.95) ÷ 1450

Torque = 52.37 N·m

So, the motor torque is about 52.37 N·m.

This is a simple three phase motor torque calculation. It also shows how three phase motor power calculation links to torque.

For a 3 phase electric motor torque calculation, you need the right voltage type. This calculator uses line-to-line voltage with line current.

Final Verdict

Our 3 phase motor torque calculator gives you a quick way to find motor shaft torque. You can use motor output power and speed. You can also use key electrical values.

The main 3 phase induction motor torque formula is:

Torque = (9550 × Output Power in kW) ÷ RPM

For an electrical input method, use voltage, current, power factor, and efficiency.

This tool is useful for motor sizing, load checks, and basic engineering work. It can also help with motor power and torque checks.

Keep in mind that starting torque is different from running torque. Starting torque needs motor data from the maker. The same applies to pull-up torque and breakdown torque.

For best results, use real motor data from the nameplate or test data.

FAQs

What is the 3 phase motor torque formula?

The basic formula is Torque = (9550 × Power in kW) ÷ RPM. It gives torque in N·m.

How do you calculate three phase motor torque?

Use motor output power and RPM. If output power isn't known, use voltage, current, power factor, efficiency, and RPM.

Can I use HP instead of kW?

Yes. Convert HP to kW first. One HP equals about 0.7457 kW.

What is the torque equation of a 3 phase induction motor?

For shaft torque, use Torque = (9550 × Output Power in kW) ÷ RPM. A true induction motor torque curve needs more motor data.

Can this work as a motor amp calculator 3 phase?

No. This tool finds torque. A motor amp calculator works in the other direction. It finds current from motor power and other values.

What is the 3 phase induction motor torque formula?

For running shaft torque, use the output power and speed formula. The motor's actual torque curve also depends on its design and load.

Is this a 3 phase AC motor torque calculation tool?

Yes. It can calculate shaft torque for a three phase AC motor when you enter valid motor data.

What unit does the calculator use?

The final torque result is shown in Newton-meters, or N·m.

Does this calculator find starting torque?

No. It finds running shaft torque. Starting torque needs motor test data or a maker's data sheet.

Why does motor speed matter?

Torque depends on both power and speed. For the same power, lower speed gives higher torque. Higher speed gives lower torque.