Induction Motor Slip Calculator
Calculate synchronous speed, signed induction-machine slip and rotor slip-frequency magnitude from supply frequency, poles and measured shaft speed.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Find synchronous speed from electrical frequency and pole count, then compare the rotor speed on the same rpm basis.
Synchronous rpm=120f/poles; slip=(synchronous rpm−rotor rpm)/synchronous rpm
Worked example
50 Hz and four poles give synchronous speed 1500 rpm. An entered rotor speed of 1440 rpm gives slip 4% and rotor slip-frequency magnitude 2 Hz.
Assumptions and input details
Even pole count and nonnegative mechanical speed are required. Rotor speed above synchronous gives negative slip in this kinematic comparison; no generating or motoring suitability is certified. Load torque, efficiency, losses, drive control, allowable speed and safe operating conditions are not determined.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
One revolution is 2π radians or 360 degrees. One minute is 60 seconds, so 1 rpm = 2π/60 rad/s. Rotational frequency in hertz counts revolutions per second.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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