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Power Unit Converter

Enter a value in any unit input field, and the system will automatically convert and display corresponding values for all other units. Click the advanced module switches to expand more unit options.

Enter Power

Enter a value in any unit input field, and other units will automatically sync and update.

W
kW
mW
PS
hp
cal/s
Btu/h
VA
kVA
var
kvar
Professional Units

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Usage Instructions

About Power Unit Converter

Power Unit Converter is a fast and precise tool for converting between various power units. It supports common units used in daily life, industry, and engineering, as well as specialized units for electrical engineering, thermodynamics, and mechanical engineering.

Key Features

  • Common Units: Watt, kilowatt, milliwatt, metric horsepower (PS), imperial horsepower (hp), calorie per second, Btu/h, volt-ampere (VA), kilovolt-ampere (kVA), var, kilovar (kvar)
  • Professional Units: Yottawatt (YW), Zettawatt (ZW), Exawatt (EW), Petawatt (PW), Terawatt (TW), Gigawatt (GW), Megawatt (MW), Microwatt (μW), Nanowatt (nW), Picowatt (pW), electrical horsepower, brake horsepower, kilocalorie per second, erg per second, Btu/s, kilogram-force meter per second, foot-pound force per second, foot-pound force per minute, decibel-milliwatt (dBm), decibel-watt (dBW)
  • Real-time Conversion: Instant conversion as you type
  • High Precision: Accurate conversion factors with appropriate decimal precision
  • Logarithmic Units: Special handling for dBm and dBW with logarithmic conversion formulas
  • Privacy Protection: All conversions performed locally in your browser

Conversion Standards

Base Unit

All conversions use Watt (W) as the base unit. Watt is the SI derived unit for power, defined as 1 W = 1 J/s (1 joule per second). Every unit has a precise conversion factor to Watt, ensuring accuracy and consistency.

Precision Rules

  • Common Units: Display up to 4 decimal places, automatically removing trailing zeros
  • Professional Units: Display up to 6 decimal places for high precision
  • Very Large/Small Values: Use scientific notation for values ≥ 1e9 or ≤ 1e-6
  • Automatic Formatting: Values automatically switch to scientific notation when appropriate

Special Notes

  • Logarithmic Units (dBm, dBW): These units use logarithmic conversion formulas. dBm = 10 × log₁₀(P/1mW), dBW = 10 × log₁₀(P/1W). Negative values are allowed.
  • Apparent Power (VA, kVA): These are apparent power units. For active power conversion, power factor (cos φ) is assumed to be 1 (pure resistive circuit).
  • Reactive Power (var, kvar): These are reactive power units, numerically equivalent to W/kW but with different physical meaning.
  • Horsepower Variants: Metric horsepower (PS) = 735.49875 W, Imperial horsepower (hp) = 745.699872 W, Electrical horsepower = 746 W, Brake horsepower (bhp) ≈ 745.7 W

Use Cases

  • Electrical Engineering: Convert between Watt, kilowatt, VA, kVA, var, kvar, dBm, dBW for power system design and analysis
  • Automotive: Convert engine power between horsepower (PS, hp, bhp) and kilowatt
  • Thermodynamics: Convert between Btu/h, Btu/s, calorie per second, and Watt for HVAC and energy systems
  • Mechanical Engineering: Convert between mechanical power units (kgf·m/s, ft·lbf/s, ft·lbf/min) and Watt
  • Telecommunications: Convert signal power between dBm, dBW, and Watt for RF and microwave engineering
  • Power Generation: Convert between large power units (MW, GW, TW) for grid and power plant capacity
  • Electronics: Convert between small power units (mW, μW, nW, pW) for low-power circuit design

FAQ

Q: How do I reset all inputs?

A: Click the "Reset" button (rotating arrow icon) in the top-right corner of the input area to clear all input data and restore to the initial state.

Q: Which units are supported?

A: Supports common units (Watt, kilowatt, milliwatt, metric horsepower, imperial horsepower, calorie per second, Btu/h, VA, kVA, var, kvar) and professional units (YW, ZW, EW, PW, TW, GW, MW, μW, nW, pW, electrical horsepower, brake horsepower, kcal/s, erg/s, Btu/s, kgf·m/s, ft·lbf/s, ft·lbf/min, dBm, dBW).

Q: What is the conversion precision?

A: All conversions use Watt as the base unit with precise conversion factors. Common units retain up to 4 decimal places, professional units retain up to 6 decimal places, and very large or very small values use scientific notation.

Q: Is data automatically saved? Will it be lost when refreshing the page?

A: Yes, input data is automatically saved to browser local storage. Refreshing the page won't cause data loss, and you can continue editing previously entered content. Data is automatically saved about 400ms after you stop typing.

Q: What are dBm and dBW? Can they be negative?

A: dBm and dBW are logarithmic power units. dBm is relative to 1 milliwatt, and dBW is relative to 1 watt. Yes, they can be negative values. For example, -30 dBm = 1 nanowatt, 0 dBm = 1 milliwatt, 30 dBm = 1 watt.