Power4all

Advanced Motor Calculator

Professional-grade calculations for HP, RPM, Torque, Motor Selection, and Engineering Analysis

Horsepower (HP) Calculator

Multiple Calculation Methods: Choose the method that matches your available parameters.
Method 1: From Torque & RPM
HP = (Torque × RPM) ÷ 5252
RPM
Method 2: From Electrical Parameters
3φ: HP = (√3 × V × I × PF × η) ÷ 746
1φ: HP = (V × I × PF × η) ÷ 746
V
A
%
Method 3: From Power (Watts)
HP = Power (Watts) ÷ 746
Method 4: From Mechanical Work
HP = (Force × Velocity) ÷ 550

RPM Calculator

RPM Calculation Methods: Different approaches for AC motors, DC motors, and mechanical systems.
Method 1: From HP & Torque
RPM = (HP × 5252) ÷ Torque
HP
Method 2: Synchronous Speed (AC Motors)
RPM = (120 × Frequency) ÷ Poles
Hz
Method 3: Actual RPM (with Slip)
Actual RPM = Sync RPM × (1 - Slip%)
RPM
%
Method 4: From Linear/Angular Velocity
RPM = (Velocity × 60) ÷ (π × Diameter)

Torque Calculator

Torque Calculation Methods: Calculate torque from various motor and mechanical parameters.
Method 1: From HP & RPM
Torque = (HP × 5252) ÷ RPM
HP
RPM
Method 2: From Force & Distance
Torque = Force × Distance
Method 3: From Current & Motor Constant
Torque = Current × Kt (Motor Constant)
A
Method 4: Load Torque (Hoisting)
Torque = (Load × Radius) ÷ Efficiency
%

Motor Selection Guide

Smart Motor Selection: Enter your application requirements and get motor recommendations.

Application Requirements

RPM

Motor Recommendations

Enter your requirements to get motor recommendations.

Unit Conversions

Power Conversion
Torque Conversion
Speed Conversion
Current Conversion
Force Conversion
Length Conversion

Motor Reference Tables

Standard AC Motor Synchronous Speeds (60 Hz)

Poles Synchronous Speed (RPM) Typical Full Load Speed Slip (%) Common Applications
2 3600 3450-3500 2.8-4.2 High-speed fans, centrifugal pumps, grinders
4 1800 1725-1750 2.8-4.2 General purpose, most common industrial applications
6 1200 1140-1180 3.3-5.0 Heavy duty, high torque applications
8 900 850-875 2.8-5.6 High torque, low speed applications
10 720 690-710 1.4-4.2 Very high torque, slow speed
12 600 575-590 1.7-4.2 Extremely high torque applications

NEMA Motor Frame Sizes & Power Ratings

Frame Size HP Range Typical Voltage Mounting Type Application
42 1/20 - 1/6 115V Face Mount Small appliances, fans
48 1/8 - 1/2 115/230V Face/Foot Mount Small pumps, blowers
56 1/4 - 3/4 115/230V Foot Mount General purpose, light duty
143T-145T 1 - 3 230/460V Foot Mount General industrial
182T-184T 3 - 7.5 230/460V Foot Mount Industrial machinery
213T-215T 7.5 - 15 230/460V Foot Mount Heavy industrial
254T-256T 15 - 25 460V Foot Mount Large industrial equipment
284T-286T 25 - 40 460V Foot Mount Heavy duty industrial

NEMA Premium Efficiency Standards (Full Load)

HP Rating 2 Pole 4 Pole 6 Pole 8 Pole
1 77.0% 85.5% 82.5% 77.0%
1.5 84.0% 86.5% 87.5% 85.5%
2 85.5% 86.5% 88.5% 86.5%
3 85.5% 89.5% 89.5% 88.5%
5 87.5% 89.5% 89.5% 88.5%
7.5 88.5% 91.0% 90.2% 89.5%
10 89.5% 91.7% 91.0% 90.2%
15 90.2% 92.4% 91.7% 91.0%
20 91.0% 93.0% 92.4% 91.7%
25 91.7% 93.6% 93.0% 92.4%

Typical Motor Current Values (Full Load)

HP 115V (1φ) 230V (1φ) 230V (3φ) 460V (3φ) 575V (3φ)
1/4 5.8 2.9 - - -
1/3 7.2 3.6 - - -
1/2 9.8 4.9 - - -
3/4 13.8 6.9 - - -
1 16 8 2.5 1.25 1.0
1.5 20 10 3.7 1.85 1.48
2 24 12 4.8 2.4 1.92
3 34 17 6.6 3.3 2.64
5 56 28 10.6 5.3 4.24
7.5 - 40 15.2 7.6 6.08
10 - 50 19.6 9.8 7.84