How Much is a Watt Calculator

Power Formula:

\[ P = V \times I \times PF \]

Voltage (V):

volts

Current (I):

amperes

Power Factor (PF):

(0 to 1)

Cost per kWh:

$/kWh

Hours of Use:

hours

Power Consumption:

Energy Used:

Cost:

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1. What is a Watt?

A watt (W) is the SI unit of power, equivalent to one joule per second. It measures the rate of energy conversion or transfer. In electrical terms, one watt is the power produced by a current of one ampere flowing through an electric potential difference of one volt.

2. How Does the Calculator Work?

The calculator uses the electrical power formula:

\[ P = V \times I \times PF \]

Where:

$ P $ — Power in watts (W)
$ V $ — Voltage in volts (V)
$ I $ — Current in amperes (A)
$ PF $ — Power factor (unitless, 0 to 1)

Cost Calculation: The calculator also determines energy cost using: \[ \text{Cost} = \left(\frac{P \times \text{Hours}}{1000}\right) \times \text{Cost per kWh} \]

3. Understanding Power Calculations

Details: Power factor accounts for phase difference between voltage and current in AC circuits. For purely resistive loads (like incandescent lights), PF = 1. For inductive loads (like motors), PF is typically 0.7-0.9.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, power factor (default 1 for DC or resistive AC loads), your local electricity cost per kWh, and hours of operation. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between watts and watt-hours?
A: Watts measure power (rate of energy use), while watt-hours measure energy (power × time). 1 kWh = 1,000 watt-hours.

Q2: Why does power factor matter?
A: Low power factor means more current is needed to deliver the same real power, increasing energy losses in distribution systems.

Q3: What's a typical cost per kWh?
A: In the US, average is about $0.13/kWh (2023), but varies by location and time of use. Industrial rates are often lower than residential.

Q4: How can I reduce my power consumption?
A: Use energy-efficient devices (LED lights, ENERGY STAR appliances), turn off unused equipment, and improve power factor for inductive loads.

Q5: What's the difference between real and apparent power?
A: Real power (watts) does actual work. Apparent power (VA) is the product of V × I. Their ratio is the power factor.