What Do Watts, Volts, Amps, and Ohms Mean?
Before diving into the specifics, it's helpful to understand how these standards are established. The Bureau International des Poids et Mesures (BIPM)—a French-based international organization—sets the global standards for weights and measures. These official definitions are documented in the BIPM’s authoritative guide, the International System of Units (SI).
To make the concept of electricity easier to grasp, a common analogy is the flow of water through a closed-pipe system. Just like water must flow continuously through pipes for the system to function, electric current must flow uninterrupted through a circuit to operate correctly.
What are Volts?
In electrical applications, volts as defined by BIPM is "the potential difference between two points of a conducting wire carrying a constant current of 1 ampere, when the power dissipated between these points is equal to 1 watt." Using the water analogy, voltage, like water pressure flowing through the pipes, is the speed at which electrons pass a point along the circuit. Volts are symbolized by a capital “V.”
For power tool batteries, volts and voltage represents the electrical potential of the battery, essentially, how much "push" it can give to the electric current. Higher voltage generally means more power for demanding tasks like drilling into concrete or cutting thick wood and faster performance.
Common voltage ratings are 12V for light tools like a power screwdriver and small drills; 18V/20V/24V for general-purpose use; and 36V/40V/80V for high-performance tools for pros and industry use.
What Are Amps?
Amps (amperes) are represented by the symbol “A.” They measure the flow of electrical current—that is, the volume of electrons moving through a circuit. The term amperage refers to the strength of this current, expressed in amperes.
For example, a 1,000-watt microwave in your home draws about 8.3 amps. By comparison, a bolt of lightning can carry nearly 20,000 amps. In everyday use, the electrical wiring in most homes is typically rated for 15 or 20 amps.
While voltage determines power, amp-hours determine runtime. Amp-hours (Ah) measure how much charge a battery can hold—essentially, how long it can run before needing a recharge. A higher Ah rating means a power tool battery can deliver power for a longer period. For example a 4.0Ah battery will last twice as long as a 2.0Ah one will. Think of amp-hours like the size of the water tank—a bigger tank lets you spray longer but doesn’t change the pressure.
What are Watts?
Watts measure the rate at which electrical power flows through a system.
This unit is calculated by multiplying the current (in amps) by the electrical potential difference (in volts). In simple terms: Volts × Amps = Watts, with watts represented by the symbol “W.”
To visualize this, think of watts like the force of water blasting through a firehose or the speed of a car on the highway—both are practical analogies for how much energy is being delivered at a given moment.
For power tools, watts mean how much power is flowing through your tool while it is being used. It is the result of both volts and amps working together. Higher wattage will mean more power for your task.
We are probably most familiar with watts in light bulbs. Wattage in light bulbs tell you how much energy is being used; not how bright it is. For example a 60-watt incandescent bulb uses 60 watts of electricity. A 10-watt LED bulb might give off the same brightness but uses far less energy. The brightness is measured in lumens, not watts. For more information see our article on Light Bulb Types: How to Choose the Best Light Bulbs.
What Are Ohms?
Ohms measure how much something slows down electricity. Imagine water flowing through a pipe: a small pipe makes it harder for water to flow, while a big pipe lets water flow easily.
Electricity works the same way. If something makes it harder for electricity to move, it has more resistance—measured in ohms. Ohms are shown with the Greek symbol Ω (Omega).
In your home wiring, wires have resistance. If the resistance (ohms) is too high, it can cause overheating or poor performance in appliances.
Tools for Measuring Electricity
A multimeter is a handheld tool that measures key electrical values:
- Voltage (V): The electrical “pressure” or potential difference in a circuit.
- Current (Amps or A): The flow of electricity.
- Resistance (Ohms or Ω): How much a component resists current.
- Power (Watts or W): Often calculated as volts × amps.
Multimeters can check outlets and switches for power, measure resistance in wires and components and troubleshoot automotive and home electrical systems.
Types of Multimeters
- Digital Multimeters (DMMs): The most common type, with accurate readings displayed on a screen—easy for beginners and professionals alike.
- Analog Multimeters: Use a needle and dial, helpful for observing fluctuations or trends in current.
Other Electrical Measurement Tools
- Clamp Meter: Measures current (amps) in a wire without disconnecting it, ideal for live circuits.
- Watt Meter: Plugs into an outlet to show how many watts a device is using—handy for household appliances.
- Power Analyzer: An advanced tool that tracks volts, amps, watts, and more in real time, often used in detailed energy studies.
Always start with the highest range setting to avoid damaging the meter.
Understanding Power at Home
Watts, volts, and amps might not be something you think about every day, but they’re essential to how your home runs. From powering your coffee maker to lighting your living room, these units of electricity help keep life moving.
On average, a home uses about 29 kilowatt-hours (kWh) of electricity daily—that’s 29,000 watts spread across appliances and devices. Here’s a quick look at how much power common household items use:
- Ceiling fan: ~65 watts
- Coffee maker: ~1,000 watts
- Stove or oven: ~2,500 watts
- Washer or dryer: 1,000–4,000 watts
Severe weather is the leading cause of power outages in homes. When the lights go out, a home standby generator can keep your household running without interruption. These generators automatically turn on during an outage, powering your lights, appliances, and more.
Portable generators are great for short-term use, but they require manual setup and frequent refueling—typically every 6 to 12 hours depending on usage. In contrast, standby generators run on natural gas or propane, so there’s no need to refuel manually. They’re available in various sizes to match your home’s power needs.
Lowe’s makes it simple to prepare your home for unexpected outages. Our team can professionally install a home standby generator tailored to your space and energy requirements. To find out more, see our Home Standby Generator Installation page.
Power Smarts: Wrapping It All Up
Electricity powers our lives, and understanding the basics—watts, volts, amps, and ohms—can help you make smarter choices at home.
Together, these elements determine how efficiently your appliances and devices operate. And when it comes to saving energy (and money), efficiency matters.
That’s why Lowe’s offers a wide selection of energy-efficient appliances, LED light bulbs, smart thermostats, and more—designed to help you reduce your energy use without sacrificing performance. Whether you're upgrading your kitchen, improving your lighting, or preparing for power outages with a generator, we’ve got the tools and tech to power your home smarter.
Explore our energy-saving solutions in-store or online and take control of your home’s power.
Frequently Asked Questions
Here are answers to some frequently asked questions on watts and volts.
What is stronger watts or volts?
Watts are a measurement of electrical power. Volts signify electrical potential. Thus watts are measuring the energy being used and are stronger than volts.
What is the difference between voltage and wattage?
Wattage is the amount of power an electric device will use to operate itself and is measured in watts. Think of this like a 60-watt light bulb. Voltage is the power that comes from the United States electrical grid, which is either 120-volts or 240-volts. Most household items will be at 120-volts while large appliances will be 240-volts.
Does higher watts mean more power?
Simply put, yes. Higher wattage appliances, for example, can
deliver more power and heat than ones having half the wattage. Higher wattage
devices however will also use more energy than lesser watt models.
How many amps are in a volt?
Amps and volts are different measurements of differing aspects of electrical current and are not directly convertible. Volts measure electrical potential and amps measure the current flow.