Most household well pumps draw between 750 and 2,200 watts while running

The wattage your well pump needs depends on the pump type, how deep your well is, and how much water you use. A shallow-well jet pump typically uses 750 to 1,500 watts. A submersible pump for a deep well usually draws 1,000 to 2,200 watts. The pump's horsepower rating — usually printed on the motor housing — is the most reliable way to estimate watts: multiply the horsepower by roughly 750 watts per horsepower for a rough figure, though actual draw varies by motor efficiency and load.

What matters most is not the pump's peak wattage but the sustained wattage it draws while the pressure tank fills. A pump that draws 2,000 watts for 30 seconds every few hours is very different from one that runs continuously. Your electrical service needs to handle the starting surge — the moment the pump motor kicks on — which can be 2 to 3 times the running wattage for a fraction of a second. If your home runs on a standard 200-amp service, you have enough capacity for any residential well pump, but if you have an older 100-amp service or live in an RV, you may need to plan around the pump's cycle time.

Key Takeaways

  • A 1-horsepower pump uses roughly 750 watts; a 2-horsepower pump uses roughly 1,500 watts; multiply the horsepower by 750 to estimate running wattage.
  • The starting surge when a pump motor turns on can draw 2 to 3 times the running wattage for a second or two, so your electrical panel must handle that spike.
  • Jet pumps for shallow wells (under 25 feet) typically draw 750 to 1,500 watts; submersible pumps for deep wells typically draw 1,000 to 2,200 watts.
  • If you are running a well pump on a generator or limited electrical service, check the pump's nameplate for the exact running and starting amperage, then multiply by your voltage to get watts.

How to read the wattage from your pump's nameplate

The most accurate number is on the pump motor itself. Look for a metal or plastic plate riveted or glued to the motor housing — usually on the side or top. This nameplate lists the horsepower, voltage (120V, 240V, or 480V), and amperage (amps). To find watts, multiply the voltage by the amperage: a 240-volt pump drawing 8 amps uses 1,920 watts while running.

The nameplate also shows the service factor, usually 1.0 or 1.15. This tells you how much overload the motor can handle briefly without damage. A service factor of 1.15 means the motor can safely run at 15 percent above its rated amperage for short periods — useful to know if your pump cycles frequently or if the pressure tank is small.

If the nameplate is missing or illegible, the horsepower rating is your next best clue. Most residential well pumps are 0.75, 1, 1.5, or 2 horsepower. Use 750 watts per horsepower as a rough estimate, but understand this is a ballpark figure — actual wattage depends on motor efficiency, which varies by manufacturer and age. A newer, high-efficiency motor may use 10 to 15 percent less power than an older one of the same horsepower.

Shallow-well jet pumps versus deep-well submersible pumps

A jet pump sits above ground and draws water up through a pipe using suction and pressure. These are common for wells under 25 feet deep. A 1-horsepower jet pump typically draws 1,000 to 1,500 watts. They are easier to service than submersible pumps because you can reach the motor, but they are louder and less efficient at depth.

A submersible pump sits inside the well casing and pushes water up rather than pulling it. These work for any depth and are the standard for wells deeper than 25 feet. A 1-horsepower submersible pump usually draws 1,000 to 1,200 watts, and a 2-horsepower model draws 1,800 to 2,200 watts. Submersible pumps are quieter and more efficient but harder to replace if they fail — you have to pull the entire pump and motor assembly out of the well.

The depth of your well affects how hard the pump works. A shallow well requires less pressure to lift water, so a smaller pump can do the job. A deep well requires more pressure, so you need a larger pump or accept slower flow. If you are replacing a pump, the depth is the first thing to confirm with your well driller or the previous owner, because installing an undersized pump will strain the motor and shorten its life.

Starting surge and electrical panel capacity

When a well pump motor starts, it draws a much higher current for a fraction of a second — typically 2 to 3 times the running amperage. This inrush current is why a pump that runs at 8 amps might draw 20 amps at startup. Your electrical panel and wiring must handle this spike, or the breaker will trip and the pump will not start.

A standard 200-amp residential service has enough capacity to handle any household well pump, even with the starting surge. If you have an older 100-amp service, a 2-horsepower pump may cause problems, especially if other large appliances (air conditioner, electric water heater, electric range) are running at the same time. In that case, you may need to upgrade your service or install a soft starter — a device that gradually ramps up the motor speed and reduces the inrush current to about 1.5 times the running amperage.

If you are running the pump on a generator or a limited power source like an RV or off-grid system, the starting surge matters even more. A generator rated for 5,000 watts may not start a 2-horsepower pump because the startup current exceeds what the generator can deliver. In that case, a soft starter or a variable-frequency drive (VFD) can help, but both add cost and complexity.

Calculating wattage for generators and backup power

If you need to run your well pump on a generator during a power outage, you must know both the running wattage and the starting wattage. The running wattage is what the pump draws once it is up and running — this is the sustained load. The starting wattage is the peak draw for the first second or two — this is what determines whether the generator can start the pump at all.

To find the starting wattage, take the running amperage from the nameplate, multiply it by 2.5, then multiply by the voltage. For example, a 240-volt pump with a running amperage of 8 amps has a running wattage of 1,920 watts (240 × 8). The starting wattage is roughly 4,800 watts (240 × 8 × 2.5). You need a generator rated for at least 5,000 watts to start this pump reliably, though 6,000 to 7,000 watts is safer to avoid straining the generator.

Many people underestimate the generator size needed for a well pump and end up with a unit that cannot start the pump. If you are buying a generator specifically to back up your well, ask the pump manufacturer or your well contractor for the exact starting amperage, then size the generator accordingly. A generator that is too small will either fail to start the pump or shut down under the load.

Pressure tank size and pump cycle time

The size of your pressure tank affects how often the pump runs and how long it runs each cycle. A larger tank stores more water, so the pump does not have to start as often. A smaller tank means the pump cycles more frequently, which increases wear on the motor and raises your electricity use over time.

A typical household pressure tank is 20, 30, or 50 gallons. A 20-gallon tank might cause the pump to cycle every 10 to 15 minutes if you are using water steadily. A 50-gallon tank might cycle every 30 to 45 minutes under the same use. Each cycle includes a startup surge, so a smaller tank means more surges per day and more stress on the electrical system and the motor. If you have an older electrical service or a small generator, upgrading to a larger pressure tank can reduce the number of startups and make the system more stable.

The pump's run time during each cycle also matters. If the pump runs for only 20 seconds per cycle, the sustained wattage draw is brief and your electrical bill reflects that. If the pump runs for 2 minutes per cycle, the sustained draw is longer. You can estimate your daily electricity use by multiplying the running wattage by the total run time per day in hours, then dividing by 1,000 to get kilowatt-hours.

Age and efficiency: older pumps use more watts

An older well pump motor may draw 10 to 20 percent more current than a newer one of the same horsepower. Motors degrade over time as bearings wear and windings accumulate heat damage. If your pump is 15 or 20 years old and you notice your electric bill climbing, the pump may be losing efficiency even if it still works.

Replacing an aging pump with a new, high-efficiency model can lower your electricity use by 10 to 15 percent. The savings add up over time, especially if the pump runs frequently. A new 1-horsepower pump might use 750 to 850 watts instead of 900 to 1,000 watts. Over a year, that difference can save 50 to 100 kilowatt-hours of electricity, depending on your usage pattern.

If you are considering a replacement, ask the pump supplier for the efficiency rating or the exact running amperage of the new model. Compare it to your current pump's nameplate amperage to estimate the savings. In many cases, the lower electricity cost over 10 to 15 years justifies the upfront cost of a new pump, especially if the old one is failing or cycling too often.

Frequently Asked Questions

Can I run my well pump on a standard household outlet?

No. Most well pumps are 240-volt and draw 8 to 15 amps, which requires a dedicated 240-volt circuit. A standard 120-volt household outlet is rated for 15 amps maximum and cannot safely power a well pump. The pump must be wired directly to the electrical panel on its own breaker.

What size breaker do I need for my well pump?

The breaker size is based on the pump's running amperage, not the starting surge. Take the running amperage from the nameplate and multiply by 1.25. A pump with 8 amps of running current needs a 10-amp breaker. The breaker protects the wiring from overheating if the pump draws too much current for too long, such as if the motor is stuck or the pump is cavitating.

Why does my well pump breaker trip when I turn it on?

The starting surge is too high for the breaker to handle, or the breaker is undersized. Check the breaker amperage against the pump's running amperage — if the breaker is only 5 amps and the pump runs at 8 amps, the breaker will trip. You may need to upgrade the breaker and the wiring, or install a soft starter to reduce the inrush current.

How much does it cost to run a well pump for a year?

Multiply the running wattage by the total hours the pump runs per year, divide by 1,000 to get kilowatt-hours, then multiply by your local electricity rate. A 1,500-watt pump running 4 hours per day uses 2,190 kilowatt-hours per year. At 12 cents per kilowatt-hour, that is about $263 per year. Rates vary widely by region and time of year, so check your electric bill for your actual rate.

Do I need a soft starter for my well pump?

Only if your electrical service is limited or your breaker trips when the pump starts. A standard 200-amp residential service handles any household pump without a soft starter. If you have a 100-amp service, an older home, or a small generator, a soft starter can prevent nuisance trips and reduce wear on the motor, but it adds $300 to $600 to the cost.