How Much Electricity Does An Electric Lawn Mower Use: Cost

An electric lawn mower usually uses about 0.2 to 1.0 kilowatt-hours (kWh) of electricity per mowing session. At a U.S. electricity rate of $0.17 per kWh, that equals roughly 3 to 17 cents per mow.

The exact cost depends on the mower type, battery size, lawn area, grass height, cutting speed, and charger losses. A corded mower uses electricity while it runs. A battery mower uses electricity when you recharge its battery.

This guide explains how to calculate electricity use, estimate charging cost, compare corded and battery mowers, and reduce energy waste.

Quick Answer: How Many Watts Does an Electric Lawn Mower Use?

Most electric lawn mowers use between 700 and 1,500 watts while running, but the mower does not always draw its full rated power. A battery mower may use less energy over a short mowing session because its motor cycles and slows when grass is light.

Typical electricity use looks like this:

Mower type	Typical energy per mowing session	Approximate cost at $0.17/kWh
Small battery mower	0.2–0.4 kWh	3–7 cents
Mid-size battery mower	0.4–0.7 kWh	7–12 cents
Large battery mower	0.7–1.0 kWh	12–17 cents
Corded mower	0.5–1.5 kWh	9–26 cents

These are useful planning ranges, not fixed ratings. A dense, wet lawn can use much more energy than a dry lawn cut at the correct height.

A battery label does not show the full electricity used from the wall. Charging creates some heat loss, so the outlet may supply about 10% to 20% more energy than the battery stores.

How to Calculate Electricity Use

The basic formula is simple:

Electricity use in kilowatt-hours = watts × hours used ÷ 1,000

For example, a 1,000-watt corded mower used for 45 minutes would use:

1,000 × 0.75 ÷ 1,000 = 0.75 kWh

At $0.17 per kWh:

0.75 × $0.17 = $0.13

So, the mowing session would cost about 13 cents.

For a battery mower, calculate the battery energy first:

Battery watt-hours = volts × amp-hours

A 40-volt battery rated at 5 amp-hours stores:

40 × 5 = 200 watt-hours

That equals:

200 ÷ 1,000 = 0.20 kWh

If charging losses add 15%:

0.20 × 1.15 = 0.23 kWh from the outlet

At $0.17 per kWh, one full charge costs:

0.23 × $0.17 = about 4 cents

A note about battery voltage

Manufacturers may list either nominal voltage or maximum voltage. A “40-volt” battery may have a slightly different operating voltage during use. Use the value printed on the battery or in the owner’s manual for a useful estimate.

The calculation also assumes a full charge. If you use half the battery, then recharge half of it, the energy cost is usually about half the full-charge cost.

Battery Lawn Mower Electricity Use

A battery mower’s electricity use depends mainly on battery capacity and how much of the battery you use.

Example: 40V, 5Ah battery

A 40V, 5Ah battery stores about 200 Wh, or 0.20 kWh.

With an estimated 15% charging loss:

• Battery energy: 0.20 kWh
• Energy from the outlet: about 0.23 kWh
• Cost at $0.17/kWh: about 4 cents per full charge

If one charge cuts your entire lawn, your electricity cost may be close to 4 cents per mow. If the battery only lasts for half the lawn, two full charges would cost about 8 cents.

Example: 60V, 7.5Ah battery

A 60V, 7.5Ah battery stores:

60 × 7.5 = 450 Wh, or 0.45 kWh

With 15% charging loss:

0.45 × 1.15 = 0.52 kWh

At $0.17 per kWh:

0.52 × $0.17 = about 9 cents

A larger battery does not automatically mean higher cost per mow. It may simply let the mower cover more ground before charging.

Energy use over a mowing season

Suppose a mower uses 0.45 kWh from the wall per mow and you mow once a week for 30 weeks:

0.45 × 30 = 13.5 kWh per season

At $0.17 per kWh:

13.5 × $0.17 = $2.30 per season

Your local rate may be much lower or higher. Check the electricity price on your utility bill. Some U.S. utilities also use time-of-use rates, so charging at a different hour can change the cost.

Corded Electric Mower Electricity Use

A corded electric mower draws power from a household outlet during operation. The most useful formula is:

Motor watts × mowing hours ÷ 1,000 = kWh used

For example, a 1,200-watt mower used for 30 minutes would use:

1,200 × 0.5 ÷ 1,000 = 0.60 kWh

At $0.17 per kWh, that costs about 10 cents.

A corded mower may use more or less than its listed wattage. The motor needs extra power when the blade meets thick or wet grass. A long or undersized extension cord can also cause voltage drop and heat.

Use an outdoor-rated extension cord with the correct gauge and length listed in the mower manual. Keep the cord behind you and away from the blade. Never mow with a damaged cord, plug, or housing.

Corded mowers have one clear energy advantage: there is no battery charging loss. They also have a practical limit. The cord must reach every part of the lawn, and the user must manage it safely.

What Changes an Electric Mower’s Energy Use?

The mower’s rated wattage is only part of the answer. These factors can change electricity use during each mowing session.

Lawn size

A larger lawn requires more operating time. If two identical mowers cut lawns of different sizes, the mower used longer will normally use more electricity.

Grass height

Tall grass makes the blade work harder. If you delay mowing, the mower may need more energy to cut the same area. Cutting no more than about one-third of the grass blade at one time can reduce strain, though the best height depends on the grass type and local growing conditions.

Wet grass

Wet grass is heavier and can clog the deck. It often increases motor load and may create poor cutting results. Mow when the grass is dry when local conditions allow.

Blade condition

A dull or damaged blade can increase cutting resistance. It can also tear grass instead of making a clean cut. Disconnect the power source before inspecting or servicing the blade, and follow the owner’s manual.

Cutting speed and drive system

Self-propelled battery mowers use extra energy to move the wheels. Steep slopes, thick grass, and soft ground can increase that demand. A push mower usually uses less electricity because it does not power a drive motor.

Deck height

A very low deck setting can increase the load on the motor. Raising the deck slightly may reduce energy use, especially in tall or dense grass.

Battery age and temperature

Lithium-ion batteries can lose capacity as they age. Very cold or hot conditions can also reduce available runtime. Store and charge the battery within the temperature limits in the manufacturer’s instructions.

How to Measure Your Mower’s Actual Electricity Use

A plug-in energy meter can measure a corded mower’s electricity use. For a battery mower, measure the charger at the wall.

For a corded mower

1. Plug an outdoor-rated energy meter into a suitable outlet.
2. Connect the mower to the meter.
3. Mow a normal section of lawn.
4. Read the watt-hours or kilowatt-hours shown.
5. Multiply the kWh value by your electricity rate.

Do not use an indoor-only meter outdoors. Keep the meter, connection, and plug away from water.

For a battery mower

1. Use the mower until the battery reaches the normal recharge point.
2. Let the battery cool if the manual requires it.
3. Plug the charger into an energy meter at a safe indoor outlet.
4. Charge the battery fully.
5. Record the kWh shown by the meter.
6. Repeat the test over two or three normal uses for a better average.

A single test can be misleading. Battery chargers may continue to draw a small amount of power after the battery indicator shows full. Unplug the charger when the manual says charging is complete, especially if the charger does not have a clear automatic shutoff.

Electric Mower Cost Compared With a Gas Mower

Electric mowing usually has a low direct energy cost, but the total ownership cost includes the mower, battery, charger, maintenance, and eventual battery replacement.

A gas mower uses fuel measured in gallons. An electric mower uses electricity measured in kWh. These units cannot be compared by price alone. The fair comparison is:

• Cost of gasoline used per mow
• Cost of electricity used per mow
• Oil and filter maintenance
• Spark plug and air filter service
• Battery and charger cost
• Expected service life
• Local fuel and electric rates

For electricity, use:

kWh per mow × local electricity price

For gasoline, use:

Gallons per mow × local gasoline price

The U.S. Department of Energy’s fueleconomy.gov explains that electric equipment can have different operating costs from gasoline equipment, but real savings depend on use and local energy prices. The U.S. Environmental Protection Agency also notes that gas-powered outdoor equipment produces direct exhaust emissions where it operates.

This does not mean every electric mower is cheaper to own. A high-priced battery mower may take years to offset its purchase cost. However, its routine energy cost is often only a few cents per mowing session.

How to Lower an Electric Mower’s Electricity Use

You can reduce energy use by reducing cutting resistance and avoiding wasted charging.

• Mow dry grass when possible.
• Keep the blade sharp and correctly installed.
• Avoid letting grass grow far above its normal height.
• Use a suitable deck height.
• Clean packed grass from the mower only after removing the battery or disconnecting the cord.
• Use a push setting instead of self-propelled drive on flat ground when practical.
• Charge only the batteries you need.
• Store batteries in the temperature range stated in the manual.
• Keep charger vents clear.
• Replace a damaged blade instead of forcing the mower through heavy grass.
• Use the manufacturer’s charger or an approved replacement.
• Unplug the charger after charging if the manual recommends it.

Do not cut safety features, bypass interlocks, modify the battery, or use an unapproved charger to save time or energy. Lithium-ion batteries can cause fire or injury if damaged, shorted, overheated, or charged with incompatible equipment.

Common Mistakes When Estimating Electricity Use

The most common mistake is treating a battery’s voltage as its energy rating. Voltage alone does not tell you how much energy the battery stores. You also need amp-hours.

Another mistake is multiplying the charger’s maximum wattage by the full charging time. A charger may draw high power at the start and lower power near the end. A wall energy meter gives a better result.

Do not assume the mower’s rated watts equal its actual average use. Ratings may describe maximum input, motor output, or a product specification that is not directly comparable with another brand’s rating.

Finally, do not compare a full battery charge with one hour of corded mowing unless both mowers cover the same area. The useful comparison is energy per lawn or energy per square foot, not energy per charge alone.

Frequently Asked Questions

Does an electric lawn mower use a lot of electricity?

No. Most residential electric mowers use less than 1 kWh for a typical mowing session. At many U.S. electricity rates, that costs less than 20 cents. Heavy grass, large lawns, and self-propelled operation can increase use.

How much does it cost to charge an electric lawn mower?

A common 40V, 5Ah battery may cost about 4 cents to charge fully at $0.17 per kWh, including an estimated charging loss. A larger battery may cost 8 to 12 cents. Use your local utility rate for a more accurate result.

Is a corded mower cheaper to run than a battery mower?

A corded mower avoids battery charging losses, so it may use slightly less electricity for the same work. In practice, the difference is often small. Lawn size, mower efficiency, grass conditions, and operating time matter more.

How many watts does a cordless lawn mower use?

A cordless mower may be described with a voltage and battery capacity instead of a running watt rating. A 40V, 5Ah battery stores about 200 Wh. The mower’s actual power draw changes with grass, blade load, speed, and drive use.

Can I leave my mower battery charging overnight?

Follow the battery and charger manual. Use the approved charger, charge on a hard nonflammable surface, keep the charger ventilated, and do not charge a battery that is swollen, cracked, wet, hot, or damaged. When the manufacturer does not recommend unattended charging, do not leave it charging overnight.

Bottom Line

An electric lawn mower normally uses about 0.2 to 1.0 kWh per mowing session, which often costs 3 to 17 cents at a U.S. rate of $0.17 per kWh. Battery size, lawn conditions, mower runtime, and charging losses determine the actual amount.

To calculate your own cost, multiply the mower’s measured kWh by the electricity rate on your utility bill. For a battery mower, start with volts × amp-hours, convert watt-hours to kilowatt-hours, and add a reasonable allowance for charging loss. A plug-in energy meter can confirm the real result.

Sources

• U.S. Department of Energy, Energy Saver: Electricity Basics and Energy Use
• U.S. Energy Information Administration: Electric Power Monthly
• U.S. Environmental Protection Agency: Nonroad Engines, Equipment, and Vehicles
• U.S. Consumer Product Safety Commission: Lithium-Ion Battery Safety