**How do you calculate torque from voltage in an electric motor?**

To compute torque from voltage in an **electric motor**, various parameters must be considered, including the motor’s electrical & mechanical properties. The link between voltage, current, & torque is indirect, requiring an understanding of the motor’s characteristics and performance curve.

Here’s a step-by-step guide:

## Step 1: Identify Motor Specifications

Obtain the following motor characteristics from the datasheet.

- The motor constant (Kt) is commonly measured in Nm/A.
- Motor Resistance (R)
- Motor back EMF constant (Ke)
- The no-load speed (ω) and current (I) are both zero.

## Step 2: Determine the Operating Conditions

Determine the motor’s operating voltage (V) and current (I). The formula for estimating the current is as follows:

**I = (V−Eb) / R**

The rear EMF (Eb) is proportional to motor speed (ω).

**Eb = Ke . ω**

## Step 3: Calculate the Back EMF

To calculate the back EMF (Eb), use the known motor speed (ω).

**Eb = Ke . ω**

## Step 4: Calculate Current Input the back EMF into Current Formula

U = (V-Ke.ω)/R

## Step 5: Calculate Torque

Finally, use the motor constant (Kt) to determine the torque (𝜏).

**τ = K t** **** **x (I** **−I 0** **)**

Optimized calculation for **DC motors:**

For a DC motor, you can simplify the torque calculation by keeping the motor constant and assuming insignificant no-load current:

**τ = K t x I**