kW to HP to kVA Calculator
Evaluate power ratings across active (kW), mechanical (HP), and apparent (kVA) electrical scales. Convert bidirectional variables using power factor properties.
Power Converter (kW, HP, kVA)
How to Use the kW to HP to kVA Calculator
Converting kilowatts to horsepower and apparent power is direct.
- 1Enter Power: Input the value in kilowatts (kW) into the designating field.
- 2Power Factor: Enter the power factor of your system (typically 0.8 to 1.0).
- 3Calculate: Click the "Calculate to kVA" button to process the conversion.
How to Convert kW to HP to kVA
In electrical design, different components utilize different power benchmarks. Generators and transformers are sized by apparent power in kilovolt-amperes (kVA); mechanical motor loads are sized by horsepower (HP); and grid active electrical power is sized by kilowatts (kW). Sizing electrical systems requires applying standard conversion ratios that account for winding efficiency and phase angle displacements (power factor).
Real-Life Sizing Scenarios
Scenario 1: Converting a Standby Generator Capacity
An electrical engineer inspects a facility standby generator rated at 100 kVA apparent power. The target building runs at a standard power factor (PF) of 0.80. Sizing the available active power (kW) and motor capacity (HP):
Active Power (kW) = 100 kVA × 0.80 PF = 80 kW
Mechanical Power (HP) = 80 kW ÷ 0.746 = 107.24 HP
Scenario 2: Sizing an Industrial Water Pump Motor
A commercial site requires a water pump driven by a motor rated at 50 HP. The motor operates with a power factor of 0.82. Converting the rating to kW and kVA (motor efficiency ignored; divide by efficiency for the actual electrical input):
Active Power (kW) = 50 HP × 0.746 = 37.30 kW
Apparent Power (kVA) = 37.30 kW ÷ 0.82 PF = 45.49 kVA
Step-by-Step Manual Sizing Guide
- 1Identify the Input unit: Settle which parameter is known (kW, HP, or kVA).
- 2Settle Power Factor: Settle the target power factor (PF). If unknown, use 0.80.
- 3Apply Conversion Formulas:
- kW to HP:
HP = kW ÷ 0.746 - kW to kVA:
kVA = kW ÷ PF - HP to kW:
kW = HP × 0.746 - kVA to kW:
kW = kVA × PF
- kW to HP:
kW to HP & kVA Sizing Table
The table below displays active power conversions to HP and kVA equivalents at a standard power factor of 0.80:
| Active Power (kW) | Power Factor (PF) | Mechanical HP Equivalent | Apparent kVA Equivalent |
|---|---|---|---|
| 1 kW | 0.80 | 1.34 HP | 1.25 kVA |
| 5 kW | 0.80 | 6.70 HP | 6.25 kVA |
| 10 kW | 0.80 | 13.40 HP | 12.50 kVA |
| 25 kW | 0.80 | 33.51 HP | 31.25 kVA |
| 50 kW | 0.80 | 67.02 HP | 62.50 kVA |
| 100 kW | 0.80 | 134.05 HP | 125.00 kVA |
HP to kW & kVA Sizing Table
The table below displays motor horsepower conversions to kW and kVA equivalents at a standard power factor of 0.80:
| Mechanical Power (HP) | Power Factor (PF) | Active kW Equivalent | Apparent kVA Equivalent |
|---|---|---|---|
| 1 HP | 0.80 | 0.75 kW | 0.93 kVA |
| 5 HP | 0.80 | 3.73 kW | 4.66 kVA |
| 10 HP | 0.80 | 7.46 kW | 9.33 kVA |
| 25 HP | 0.80 | 18.65 kW | 23.31 kVA |
| 50 HP | 0.80 | 37.30 kW | 46.63 kVA |
| 100 HP | 0.80 | 74.60 kW | 93.25 kVA |
kVA to kW & HP Sizing Table
The table below displays apparent power conversions to kW and HP equivalents at a standard power factor of 0.80:
| Apparent Power (kVA) | Power Factor (PF) | Active kW Equivalent | Mechanical HP Equivalent |
|---|---|---|---|
| 1 kVA | 0.80 | 0.80 kW | 1.07 HP |
| 5 kVA | 0.80 | 4.00 kW | 5.36 HP |
| 10 kVA | 0.80 | 8.00 kW | 10.72 HP |
| 25 kVA | 0.80 | 20.00 kW | 26.81 HP |
| 50 kVA | 0.80 | 40.00 kW | 53.62 HP |
| 100 kVA | 0.80 | 80.00 kW | 107.24 HP |
1 HP to kVA Calculation
Converting a standard baseline rating of 1 HP to apparent power (kVA) requires converting the mechanical rating to active electrical power before dividing by power factor. Sizing at a standard power factor of 0.80:
kW = 1 HP × 0.746 = 0.746 kW
kVA = 0.746 kW ÷ 0.80 = 0.9325 kVA
HP to kVA Formula 3 Phase
For three-phase AC induction motors, sizing the apparent power in kVA from horsepower (HP) uses the overall motor rating. Sizing does not divide by √3 directly since HP represents total mechanical output, but it incorporates motor efficiency (η):
kVA = (HP × 0.746) ÷ (PF × η)
This kVA rating is used by designers to size local circuit breakers and feeder wire ampacities.
kW to kVA Formula 3 Phase
Converting three-phase active real power (kW) to apparent power (kVA) is governed by the system power factor: kVA = kW ÷ PF. In a balanced three-phase system, this relationship remains identical to single-phase conversions since both represent cumulative system values. Phase current variables (requiring √3) only apply when resolving line currents from the total kVA rating.
10 HP to kVA
Converting a 10 HP motor rating to apparent power at a standard power factor of 0.80 (motor efficiency ignored; dividing by efficiency gives the actual input kVA):
Active Power = 10 HP × 0.746 = 7.46 kW
Apparent Capacity = 7.46 kW ÷ 0.80 = 9.325 kVA
15 HP to kVA
A standard 15 HP industrial motor converts to apparent power based on PF (and efficiency, ignored here). Sizing at a power factor of 0.80:
Active Power = 15 HP × 0.746 = 11.19 kW
Apparent Capacity = 11.19 kW ÷ 0.80 = 13.99 kVA
100 HP to kVA
A heavy-duty 100 HP motor requires significant starting and running apparent power capacity. Sizing at a standard power factor of 0.80:
Active Power = 100 HP × 0.746 = 74.60 kW
Apparent Capacity = 74.60 kW ÷ 0.80 = 93.25 kVA
50 HP to kVA
Sizing generator requirements to feed a 50 HP motor requires calculating the apparent power load. Sizing at a power factor of 0.80:
Active Power = 50 HP × 0.746 = 37.30 kW
Apparent Capacity = 37.30 kW ÷ 0.80 = 46.63 kVA
Frequently Asked Questions (FAQs)
At a standard power factor of 0.80, 1 kVA apparent power equals 0.80 kW active power. Converting to horsepower gives: 0.80 kW ÷ 0.746 = 1.072 HP.
Dividing active power by power factor yields apparent power. Sizing at a standard power factor of 0.80: 1 kW ÷ 0.80 = 1.25 kVA.
To convert horsepower to apparent power, multiply the HP rating by 0.746 to convert to kilowatts, and then divide by the system power factor (PF): kVA = (HP × 0.746) ÷ PF.
To find kilowatts, multiply apparent power by the system power factor. Sizing at a standard power factor of 0.80: 70 kVA × 0.80 = 56 kW.
A 100 kVA generator supplying power at a standard power factor of 0.80 can handle a continuous active real power load of 80 kW.
Assuming a standard 0.80 power factor, a 5 HP motor corresponds to: (5 × 0.746) ÷ 0.80 = 4.6625 kVA.
