Slow Cooker Energy Cost Calculator

How the Slow Cooker Cost Formula Works

Electricity companies bill you using kilowatt-hours (kWh). One kWh is the energy used by a 1,000 watt appliance running for one hour. To estimate the cost of a slow-cooked meal, you need three things:

• The slow cooker’s power rating in watts (W).
• The total cooking time in hours.
• Your electricity rate in cost per kWh (for example, $0.13 per kWh).

The basic steps are:

1. Convert watts to kilowatts by dividing by 1,000.
2. Multiply by the number of hours you cook to get kWh.
3. Multiply the kWh by your electricity rate to get the cost.

In plain language, the formula is:

Cost = (Wattage ÷ 1,000) × Cooking Time (hours) × Electricity Rate (per kWh)

The same relationship can be written using MathML for browsers and assistive technologies that support it:

Where:

• C is the estimated cost of running the slow cooker for one session.
• W is the slow cooker wattage in watts.
• H is the cooking time in hours.
• R is your electricity rate per kWh.

Worked Examples

Example 1: Typical Weeknight Meal

Suppose your slow cooker uses 200 watts and you cook a stew for 8 hours. Your electricity rate is $0.13 per kWh.

1. Convert watts to kilowatts: 200 W ÷ 1,000 = 0.2 kW.
2. Multiply by hours: 0.2 kW × 8 h = 1.6 kWh.
3. Multiply by rate: 1.6 kWh × $0.13/kWh = $0.208.

Estimated cost: about $0.21 for that 8-hour meal.

Example 2: All-Day Cooking (10 Hours)

Now imagine a slightly larger slow cooker that uses 250 watts, running for 10 hours at the same $0.13 per kWh rate.

1. Convert watts to kilowatts: 250 W ÷ 1,000 = 0.25 kW.
2. Multiply by hours: 0.25 kW × 10 h = 2.5 kWh.
3. Multiply by rate: 2.5 kWh × $0.13/kWh = $0.325.

Estimated cost: about $0.33 for a full day of cooking.

From Single Meal to Monthly or Yearly Cost

The calculator shows the cost for one cooking session, but you can scale it up easily. Using the first example cost of $0.21 per meal:

• If you use the slow cooker twice a week: 2 × $0.21 = $0.42 per week.
• Over a year: $0.42 × 52 weeks ≈ $21.84 per year.

Even with frequent use, the total annual electricity cost for a typical slow cooker is usually modest compared with other large appliances.

Slow Cooker vs Oven Energy Cost

Many long-cooking recipes can be made either in a slow cooker or in a conventional oven. Ovens generally draw much more power, but they might run for fewer hours. The table below compares a typical scenario:

Assumptions:

• Slow cooker: 200 watts for 8 hours.
• Oven: 2,400 watts for 2 hours.
• Electricity rate: $0.13 per kWh.

In this example, the oven uses about three times as much energy as the slow cooker for a similar finished dish. The exact difference for your home will depend on the wattage of your specific appliances and your local electricity rate.

How to Use This Slow Cooker Energy Cost Calculator

1. Enter slow cooker wattage (W). You can usually find this on a label on the bottom of the appliance or in the user manual. Common values range from about 150 W to 300 W.
2. Enter cooking time in hours. Use the total time the slow cooker is on, including time on a “keep warm” setting if you leave it running.
3. Enter your electricity rate. This is the price you pay per kWh. You can find it on your electric bill. In many parts of the U.S., it is roughly $0.12–$0.20 per kWh; the default value of $0.13 is a typical average.
4. View the result. The calculator shows the estimated cost to run the slow cooker for that one cooking session.

You can adjust the wattage to compare low and high settings if your model lists different power ratings for each mode.

Interpreting Your Results

The output from the calculator gives you the estimated electricity cost for a single use of your slow cooker. You can use this figure in several ways:

• Cost per meal: If you are cooking a recipe that serves several people, divide the cost by the number of servings to get an approximate cost per portion.
• Weekly or monthly cost: Multiply the per-session cost by the number of times you use the slow cooker each week or month.
• Comparing with other appliances: Use the same formula or a related calculator for your oven, pressure cooker, or air fryer to see which option is cheaper for similar recipes.

Remember that electricity is only one part of the total food cost. Ingredients, time saved, and reduced need for takeout can matter even more than the small differences in appliance energy use.

Common Questions About Slow Cooker Energy Use

Is it cheaper to run a slow cooker or an oven?

In many cases, a slow cooker is cheaper to run for long, low-temperature recipes. A typical slow cooker might use 150–300 watts, whereas an electric oven can draw 2,000–3,500 watts. Even though the oven runs for fewer hours, the higher power draw often leads to higher total energy use. The comparison table above shows one example; you can adjust the inputs in the calculator to model your own appliances.

How many kWh does a slow cooker use?

The kWh used by a slow cooker depends on both wattage and time. For a 200 watt unit:

• 4 hours: (200 ÷ 1,000) × 4 = 0.8 kWh.
• 8 hours: (200 ÷ 1,000) × 8 = 1.6 kWh.
• 10 hours: (200 ÷ 1,000) × 10 = 2.0 kWh.

You can enter different combinations into the calculator to see the corresponding cost at your electricity rate.

How much does it cost to run a slow cooker all day?

Using the earlier example of a 250 watt slow cooker at $0.13 per kWh for 10 hours, the cost was about $0.33. If you run the same cooker for 12 hours, the cost would be:

(250 ÷ 1,000) × 12 × $0.13 ≈ 0.25 × 12 × 0.13 = 3.0 × 0.13 = $0.39.

Even a full day of slow cooking usually costs well under a dollar in electricity in many regions.

Tips for Efficient Slow Cooking

• Keep the lid on. Lifting the lid lets heat escape and can extend cooking time, which may slightly increase energy use.
• Match the pot size to the recipe. Using a very large slow cooker for a small batch can be less efficient.
• Use the low setting when possible. Many recipes work well on the low setting, which typically uses less power than high.
• Batch cook and freeze. Cooking larger quantities and freezing portions spreads the energy cost over more meals.
• Avoid unnecessary preheating. Most slow cooker recipes do not require long preheating times.

Assumptions and Limitations

This calculator provides an estimate, not an exact bill. It is based on several simplifying assumptions:

• Constant wattage: The calculation assumes the slow cooker draws its rated wattage the entire time. In reality, many models cycle on and off to maintain temperature, so actual usage may be somewhat lower or higher.
• Flat electricity rate: The calculation uses a single rate per kWh that you enter. If your utility uses tiered pricing, time-of-use rates, or additional fees, your real cost can differ.
• Model differences: Some slow cookers have more efficient insulation or different power levels for warm, low, and high settings. If your appliance lists separate wattages for each mode, use the value that best matches how you cook.
• No standby or preheat overhead: Standby power when the appliance is plugged in but off, or short preheating periods, are not modeled separately here.

Typical wattage values and cost ranges in the examples are based on common manufacturer specifications and publicly available energy cost data. Because rates and appliance designs vary by region and brand, your actual costs may differ. Use your own bill and appliance labels for the most accurate estimates.