Power Converter

Power Converter

Convert rates of energy transfer across electrical, mechanical, heating, and cooling labels. The converter uses watts as the common route so horsepower, Btu per hour, kilowatts, megawatts, and work-rate units can be compared directly.

Live converter

Power conversion inputs

Convert rates of energy transfer across watts, kilowatts, megawatts, mechanical horsepower, Btu per hour, foot-pounds per second, and calories per second.

hp

Converted result

745.699871582 W

Input

1 hp

Output unit

W

Base method

watts

Power in every supported unit

UnitConverted valueUnit nameNote
W745.699871582WattsSI derived unit of power.
kW0.745699871582Kilowatts1,000 watts.
MW0.000745699871582Megawatts1,000,000 watts.
hp1Mechanical horsepowerMechanical horsepower.
Btu/h2,544.43357764Btu per hourHeating and cooling rate.
ft lbf/s550Foot-pounds per secondMechanical work rate.
cal/s178.226546745Calories per secondHeat-rate unit.

Base unit

watt

Supported units

7

Includes

hp + Btu/h

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What Can You Create?

Convert equipment power, heat rate, and mechanical output

Electrical ratings

Convert watts, kilowatts, and megawatts for equipment, generator, and utility notes.

Mechanical output

Translate mechanical horsepower and foot-pounds per second into watts.

Heating and cooling

Compare Btu per hour with watt-based power values for HVAC references.

Formula

Power conversion formula

The converter normalizes each source value into watts, then divides by the watt factor for the target unit.

Working formulas

Base conversion

watts = value x watts per source unit

Watts provide the common route for electrical, mechanical, and thermal power units.

Target value

target value = watts / watts per target unit

The watt value is scaled into the selected target unit.

Mechanical horsepower

1 hp = 745.6998715822702 W

Mechanical horsepower is distinct from metric horsepower and electrical horsepower.

Symbols

W - watt
SI derived unit of power, equal to one joule per second.
hp - mechanical horsepower
A common mechanical output rating.
Conversion Guide

Power rates, horsepower definitions, and energy over time

This live converter translates a rate of energy transfer through watts. It is not an equipment-selection table and it does not turn a power rating into energy use until a duration is supplied separately.

Watts and named rate units

One watt is one joule per second. SI prefix scales are exact, so 1 kW is 1,000 W and 1 MW is 1,000,000 W. Btu/h, ft lbf/s, and cal/s are converted by applying the page's documented energy factor and the stated time denominator.

The hp row specifically means mechanical horsepower at 745.6998715822702 W. Metric and electrical horsepower are different definitions, so an unlabeled horsepower value should be identified before it is copied into a technical comparison.

Worked relationship: 2 kilowatts over three hours

2 kW = 2,000 W; 2 kW x 3 h = 6 kWh

The first equality is a power conversion performed by this page. The second calculation introduces time and therefore produces energy, which belongs in kilowatt-hours rather than kilowatts.

Compare like-for-like ratings

The display keeps up to 12 significant digits for factor checks, but equipment labels often warrant fewer. Preserve whether a value is input power, shaft output, thermal capacity, or another stated rating before comparing two devices.

Copy compound-unit denominators exactly. Btu/h is power while Btu is energy; cal/s is power while cal is energy. The slash and time unit carry essential meaning.

Use this page for rate-to-rate conversion. Use the energy converter when the source already includes elapsed time, such as Wh, kWh, joules, or Btu.

Open the energy converter for accumulated amounts

Limits to keep with the result

  • No efficiency, duty cycle, power factor, heat loss, or load profile is inferred from a nameplate value.
  • Mechanical horsepower is the only horsepower definition in this registry.
  • Power alone cannot determine energy use or cost without duration and, for cost, an applicable tariff.
Why Users Love This Tool

Why watt-based conversion is clearer

Keeps power separate from energy

  • Watts measure a rate, while joules and kWh measure energy.
  • The table helps compare ratings without accidentally treating kW and kWh as the same thing.
  • Mechanical and thermal power labels are normalized through one SI route.

Practical equipment checks

  • Horsepower, Btu/h, and kilowatt ratings can be compared in one table.
  • The formula block identifies mechanical horsepower specifically.
  • Large power ratings remain readable for generators, motors, and building systems.
Perfect For

Useful for electrical and mechanical ratings

Electrical planning

Convert device, generator, and load ratings between W, kW, and MW.

Mechanical work

Compare horsepower and foot-pounds per second with watt-based ratings.

HVAC references

Translate Btu per hour into watts when heating and cooling data meets SI notes.

How It Works

How it works in three quick steps.

1

Enter the power rating

Type a value from equipment specs, HVAC notes, electrical ratings, or mechanics examples.

2

Select source and target units

Choose watts, kilowatts, megawatts, mechanical horsepower, Btu per hour, foot-pounds per second, or calories per second.

3

Compare the watt table

Use the table to see how electrical, mechanical, and heating/cooling power labels relate.

Download & Print

Save power conversions

Copy labeled results

Copy the selected conversion with source and target unit labels for recipes, vehicle notes, utility comparisons, or homework.

Print the comparison table

Print the full table when repeated conversions need to stay visible at a counter, desk, shop, lab, or classroom.

Keep the method nearby

Use the formula notes to confirm whether the converter used milliliters, km/L, joules, or watts as the base route.

FAQ

Frequently Asked Questions

What is the difference between energy and power?
Energy is an amount, while power is a rate. A joule is energy, and a watt is one joule per second. Kilowatt-hours measure energy used over time, while kilowatts measure the rate at which energy is transferred or consumed.
Which horsepower does this converter use?
This page uses mechanical horsepower, equal to 745.6998715822702 watts. Other horsepower definitions exist, including metric horsepower and electrical horsepower, so the label matters when comparing specifications.
How do Btu per hour and watts relate?
Btu per hour is a power unit often used in heating and cooling. The converter turns Btu/h into watts by converting Btu into joules and hours into seconds, which lets HVAC ratings be compared with SI power values.
Can I convert kW to kWh here?
Not directly, because kW is power and kWh is energy. To convert power into energy, you must also know the duration. For example, 2 kW used for 3 hours equals 6 kWh of energy.
Why use watts as the base unit?
Watts are the SI derived unit of power, so they are the clearest common route across electrical, mechanical, and thermal power labels. Normalizing to watts makes the conversion factors auditable.
About This Tool

About this power converter

Power conversions are often confused with energy conversions because labels such as kW and kWh look similar. A watt is a rate of energy transfer, while a kilowatt-hour is an amount of energy accumulated over time. This page keeps those ideas separate by focusing only on power units.

The converter uses watts as the base route for electrical units, mechanical horsepower, foot-pounds per second, calories per second, and Btu per hour. That makes it useful for comparing equipment specifications, motor ratings, generator loads, and HVAC notes without manually rebuilding the factor chain every time.

Editorial Transparency

Who maintains this page

Ownership and review

Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.

Methodology

Conversion factors are normalized to canonical units and checked in both directions. Exact definitions and offset formulas are preferred over rounded lookup values.

Read the editorial methodology

Dates and sources

Review dates change only after a substantive method or content check.

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