HP to kW

Convert Horsepower to Kilowatts instantly with our Performance Garage engine. Features DIN Metric HP (PS) vs SAE Mechanical HP (BHP) switching, real-world engine matcher, electrical tool breaker estimator, and dynamic SVG tachometer.

Unit Converters

Global Horsepower Standard

Active Standard: DIN 70020 Metric Horsepower (1 PS = 735.499 W). Standard on European vehicle registration documents and Asian vehicle specs.

Metric Horsepower (PS)DIN 70020

DIN 70020 Standard (Europe/Asia)

Equivalent:147.95 BHP(SAE J1349)

Road & Passenger Vehicles150 PS / 110.3 kW

Kilowatts (kW)SI Standard

Global SI Scientific Standard

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Real-World Engine & Machine Matcher

Typical 1.5L Turbocharged Engine (e.g. 1.5 EcoBoost / 1.5 TSI)

Mid-Tier Turbo

Quick Automotive & Power Presets

Supply Voltage

Load Characteristics

Running Amperage

564.3A

Est. Motor Startup Surge

1410.7A

Breaker Capacity Reference

16A Residential Rating

Circuit Breaker Tripping Risk⚠️ Tripping Hazard: Exceeds standard 16A/15A residential breaker! Requires a dedicated 20A/32A line or 3-phase supply.

European Automotive Power & Car Tax Reference

Automotive taxation frameworks, registration power units, and high-performance thresholds across European jurisdictions.

Jurisdiction	Official Power Unit	Taxation & Fiscal Basis	Performance / Luxury Surcharges
Germany	kW (Kilowatt) & PS (DIN)	Displacement (cc) + CO2 emissions (g/km) for ICE vehicles; pure EV tax exemption up to 10 years.	Insurance type classes (Typklassen) scale heavily above 110 kW (150 PS) and 221 kW (300 PS).
France	kW & CV (Puissance Fiscale)	Puissance Administrative (CV fiscaux): Pa = 1.80×(kW/100)² + 3.87×(kW/100) + 1.34.	Regional registration fee per CV fiscal; severe Malus Écologique above specific CO2 & weight ratings.
Italy	kW & CV (Cavalli Vapore)	Tassa Automobilistica (Bollo Auto) charged per kilowatt (~€2.58 to €3.87/kW depending on Euro class).	Superbollo: Surcharge of €20 per kW for every kilowatt exceeding 185 kW (~252 CV).
Spain	kW & CV (Caballos Fiscales)	IVTM road tax based on Potencia Fiscal (CVF), derived from displacement or kW rating (kW/0.735 × 0.08).	Steep tax bracket increases above 16 CVF (~120-140 kW) and 20 CVF (~180 kW).
Romania	kW & CP (Cai Putere)	Annual local motor tax graduated per 200 cc increments; 100% electric vehicles are exempt (0 RON).	Official RAR vehicle identity card (CIV) registers kW as SI base and CP metric as commercial standard.
Portugal	kW & cv (Cavalos-Vapor)	IUC (Imposto Único de Circulação) based on cylinder capacity brackets and WLTP CO2 emissions.	Electric vehicles 100% exempt from IUC; additional luxury surcharges applied to high-emission vehicles.
US / UK Standard	BHP (Brake HP) & kW	US Monroney window stickers list SAE net BHP; UK VED uses CO2 bands and £40k+ luxury car surcharge.	Dynamometer SAE J1349 flywheel horsepower reflects gross output before auxiliary accessory parasitic losses.

How to Convert Horsepower to Kilowatts (HP to kW)

A step-by-step guide to calculating engine output, electrical kilowatt equivalents, and circuit load with dyno precision.

Enter Horsepower Output

Type the engine or motor power in horsepower (HP) into the primary input box.

Select Horsepower Standard (DIN vs SAE)

Toggle between European Metric Horsepower (PS/CV: 1 HP = 0.7355 kW) and Imperial Mechanical Horsepower (BHP: 1 HP = 0.7457 kW).

Read Kilowatts Output in Real Time

The exact power in kilowatts (kW) updates dynamically without lag or page refresh.

Analyze Live SVG Power Gauge

Watch the instrument cluster gauge dial react dynamically with tachometer glow, redline warning, and visual tier badge.

Check Electrical Breaker Load (Optional)

For workshop electric motors and tools, view running amperage, motor startup inrush current, and residential breaker safety limits.

Copy Specifications or Consult Tax Guide

Export comprehensive power and electrical specifications with one click, or review the European automotive road tax matrix below.

Frequently Asked Questions (FAQ)

Expert answers regarding metric vs mechanical horsepower, official EU kW registration standards, and motor electrical loads.

Q:What is the exact difference between Metric Horsepower (PS/CV/CP) and Mechanical Horsepower (BHP)?

Metric HP (DIN 70020, German PS, French CV, Italian CV, Romanian CP) is defined as 75 kg·m/s = 735.49875 Watts. Mechanical HP (SAE J1349 / Imperial BHP) is defined as 550 ft·lb/s = 745.69987 Watts. 1 BHP is approximately 1.01387 Metric PS (or 1 Metric PS ≈ 0.98632 BHP). An engine rated at 300 PS produces approximately 295.9 BHP.

Q:What is the exact mathematical formula to convert HP to kW?

For Metric HP (PS/CV/CP): kW = HP × 0.73549875. For Mechanical HP (BHP): kW = BHP × 0.74569987. For example, a 150 PS metric engine equals 150 × 0.73549875 ≈ 110.32 kW.

Q:What is the exact mathematical formula to convert kW to HP?

For Metric HP (PS/CV/CP): HP = kW × 1.3596216 (or kW / 0.73549875). For Mechanical HP (BHP): BHP = kW × 1.3410221 (or kW / 0.74569987). For example, 110 kW equals 110 × 1.35962 ≈ 149.56 metric PS (147.51 BHP).

Q:Why do car registration documents (carte grise, Fahrzeugschein, talon) across Europe specify engine power in kW instead of HP?

The Kilowatt (kW) is the official SI (International System of Units) scientific standard for power worldwide (EU Directive 80/181/EEC). In official vehicle registration certificates across Germany, France, Italy, Spain, Romania, and Portugal, engine power is strictly recorded in kW to ensure legal uniformity across borders and accurate calculation of emissions and road tax.

Q:How do I calculate the electrical amperage required to run an electric motor of a given HP or kW?

For single-phase 230V: Amperage (I) = (Power in Watts) / (Voltage × Power Factor cos φ). For example, a 2.2 kW (3 HP) single-phase motor at 230V with cos φ = 0.85 draws ~11.2 Amps continuously, but can draw 25–28 Amps during inductive startup (inrush current).

Q:What is Fiscal Horsepower (CV fiscaux, Steuer-PS, Potencia Fiscal) and how is it related to actual power?

Fiscal horsepower is an administrative formula used by tax authorities for vehicle registration fees and annual road taxes. It does not measure physical mechanical power; historical formulas evaluated cylinder displacement and bore/stroke, whereas modern formulas (such as in France or Spain) calculate fiscal rating using a combination of CO₂ emissions and maximum power in kW.

1. Metric Horsepower (DIN 70020 - European / Automotive):

P_(kW) = P_(PS) × 0.7355

2. Mechanical / Imperial Horsepower (SAE J1349 - US / UK):

P_(kW) = P_(hp) × 0.7457

1 PS / Metric HP: = 0.73549875 kW (standard in Continental Europe).
1 hp / Mechanical HP: = 0.74569987 kW (standard in US & UK).

Horsepower to Kilowatt Conversion Table

Horsepower [hp]	Kilowatt [kW]
0.01 hp	0.007457 kW
0.1 hp	0.07457 kW
1 hp	0.7457 kW
2 hp	1.4914 kW
3 hp	2.2371 kW
5 hp	3.7285 kW
10 hp	7.457 kW
20 hp	14.914 kW
50 hp	37.285 kW
100 hp	74.57 kW
1,000 hp	745.7 kW

What is HP to kW?

Convert Horsepower to Kilowatts instantly with our Performance Garage engine. This professional platform eliminates the confusion between global power standards by integrating a strict DIN Metric HP vs SAE Mechanical HP toggle. The dynamic SVG tachometer visually ramps up to reflect the exact power band. For heavy-duty shop planning, the electrical tool breaker estimator evaluates the converted kilowatt load against standard voltage supplies to prevent blown fuses, while the real-world engine matcher compares your numerical output to famous automotive engines for instant scale.

Practical Calculation Example

A custom hot rod builder in Detroit is swapping a modern European crate engine rated at 350 kW into a classic American muscle car. They input the value and select the DIN Metric HP toggle to find the precise equivalent. The real-world engine matcher immediately highlights that the power output perfectly mirrors a modern sports car. To ensure the new high-capacity air compressor for the paint booth won't overload the shop's electrical grid, they punch its horsepower rating into the electrical tool breaker estimator to verify the exact amperage draw on a 240V circuit.

Reference Zones

Interface Element	Engineering Function	Practical Application
DIN Metric vs SAE Mechanical	Power Calibration	Shifts the multiplier to account for the slight mathematical difference between European and American horsepower.
Dynamic SVG Tachometer	Visual Feedback	Provides a real-time dial animation representing the calculated power output.
Real-World Engine Matcher	Contextual Scaling	Links the raw kW or HP number to a recognizable vehicle engine for better spatial understanding.
Electrical Tool Breaker Estimator	Load Calculation	Derives the expected amperage draw from the power rating to prevent circuit overloads.

History and Origin

The concept of "horsepower" was famously coined by the Scottish inventor James Watt in the late 18th century. To market his highly efficient steam engines, Watt needed a metric that customers could understand, so he calculated the average power of a draft horse turning a mill wheel. He defined 1 mechanical horsepower as 33,000 foot-pounds of work per minute, a standard that irrevocably shaped the industrial revolution and modern automotive engineering.

What is Horsepower?

Definition & Usage

Horsepower (symbol: hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors.

What is Kilowatt?

Definition & Usage

The kilowatt (symbol: kW) is a unit of power, equal to 1,000 watts. This unit is typically used to express the output power of engines and the power of electric motors, tools, machines, and heaters.