Power is the rate at which work is done or energy is transferred. It is commonly measured in watts (W), kilowatts (kW), megawatts (MW), gigawatts (GW), decibel-milliwatts (dBm), decibel-watts (dBW), horsepower (hp), and BTU/hr.

Units and Conversion

• Milliwatt (mW): 1 mW = 0.001 W
• Watt (W): The base unit of power in the International System of Units (SI).
• Kilowatt (kW): 1 kW = 1,000 W
• Megawatt (MW): 1 MW = 1,000,000 W
• Gigawatt (GW): 1 GW = 1,000,000,000 W
• Decibel-milliwatts (dBm): 1 dBm = 1 mW
• Decibel-watts (dBW): 1 dBW = 1 W
• Horsepower (mechanic) (hp(I)): 1 hp(I) ≈ 745.7 W
• Horsepower (electric) (hp(E)): 1 hp(E) = 746 W
• BTU/hr: 1 BTU/hr ≈ 0.293071 W

Examples

Example 1: Convert 5 kW to W:

5 kW = 5 × 1,000 W = 5,000 W

Example 2: Convert 10 hp(I) to W:

10 hp(I) ≈ 10 × 745.7 W ≈ 7,457 W

Intensity is the power per unit area carried by a wave. It is commonly measured in watts per square meter (W/m²), kilowatts per square meter (kW/m²), milliwatts per square meter (mW/m²), microwatts per square meter (µW/m²), and decibels.

Units and Conversion

• Milliwatt per square meter (mW/m²): 1 mW/m² = 0.001 W/m²
• Watt per square meter (W/m²): The base unit of intensity.
• Kilowatt per square meter (kW/m²): 1 kW/m² = 1,000 W/m²
• Decibel-milliwatts per square meter (dBm/m²): 1 dBm/m² = 1 mW/m²
• Decibel-watts per square meter (dBW/m²): 1 dBW/m² = 1 W/m²

Examples

Example 1: Convert 5 kW/m² to W/m²:

5 kW/m² = 5 × 1,000 W/m² = 5,000 W/m²

Example 2: Convert 500 mW/m² to W/m²:

500 mW/m² = 500 × 0.001 W/m² = 0.5 W/m²

Example 3: Convert 40 dBm/m² to W/m²:

40 dBm/m² = 10^((40 - 30)/10) mW/m² = 10 W/m²

Example 4: Convert 30 dBW/m² to W/m²:

30 dBW/m² = 10^30 W/m² = 1,000,000,000,000,000,000 W/m²