Motor Slip Calculator

How Motor Slip works

The calculation uses slip = (Ns − N) ÷ Ns × 100. Motor Slip uses Synchronous speed, Measured speed to report Motor slip. For motor energy, use Motor Energy Consumption Calculator.

With the loaded values, motor slip evaluates to 4.00%. Preserve the baseline before changing a value.

Inputs for Motor Slip

Synchronous speed and Measured speed belong to Motor Slip. Keep source units with synchronous speed.

The opening values are placeholders for testing the arithmetic.

Synchronous speed

Example entry: 1500 rpm.

Measured speed

Example entry: 1440 rpm.

Reading the Motor Slip result

This output represents Motor Slip.

Finish the selection with standard sizes, operating limits, and transient review. Compare this result with Locked-Rotor kVA Calculator when locked-rotor kVA is also needed.

Measurement and units

Motor nameplate data, duty, enclosure, starting method, load profile, and thermal limits govern final selection. Check prefixes on synchronous speed. If the next question concerns capacitive reactance target, open Motor Capacitor Calculator.

Use the same unit basis and observation location in alternate cases.

Limits of this calculation

Use stable loaded speed.

This equation represents one relationship rather than a full circuit simulation. Unentered effects remain outside Motor Slip.

A useful Motor Slip comparison

Record motor slip before testing a different synchronous speed value.

Document the alternate synchronous speed source. Use Motor Acceleration Time Calculator as the follow-up for acceleration time.

Questions about Motor Slip