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calories (cal) to Kilowatt-hours (kWh) conversion

calories to Kilowatt-hours conversion table

calories (cal)	Kilowatt-hours (kWh)
0	0
1	0.000001162222222222
2	0.000002324444444444
3	0.000003486666666667
4	0.000004648888888889
5	0.000005811111111111
6	0.000006973333333333
7	0.000008135555555556
8	0.000009297777777778
9	0.00001046
10	0.00001162222222222
20	0.00002324444444444
30	0.00003486666666667
40	0.00004648888888889
50	0.00005811111111111
60	0.00006973333333333
70	0.00008135555555556
80	0.00009297777777778
90	0.0001046
100	0.0001162222222222
1000	0.001162222222222

How to convert calories to kilowatt-hours?

Converting calories to kilowatt-hours involves understanding the relationship between these two units of energy. The conversion is the same regardless of whether you are using base 10 or base 2. Let's break down the process.

Understanding the Conversion

Calories (cal) and kilowatt-hours (kWh) are both units of energy, but they are used in different contexts. Calories are commonly used to measure the energy content of food, while kilowatt-hours are used to measure electrical energy consumption.

1 calorie (cal) is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.
1 kilowatt-hour (kWh) is the amount of energy used by a 1-kilowatt device operating for 1 hour.

The Conversion Factor

The key to converting between calories and kilowatt-hours is the following conversion factor:

1 \text{ cal} = 4.184 \text{ Joules (J)}

1 \text{ kWh} = 3.6 \times 10^6 \text{ Joules (J)}

Converting 1 Calorie to Kilowatt-hours

To convert 1 calorie to kilowatt-hours, follow these steps:

Convert calories to joules: $1 \text{ cal} \times 4.184 \frac{\text{J}}{\text{cal}} = 4.184 \text{ J}$
Convert joules to kilowatt-hours: $4.184 \text{ J} \div (3.6 \times 10^6) \frac{\text{J}}{\text{kWh}} \approx 1.1622 \times 10^{-6} \text{ kWh}$

Therefore:

1 \text{ cal} \approx 1.1622 \times 10^{-6} \text{ kWh}

Converting 1 Kilowatt-hour to Calories

To convert 1 kilowatt-hour to calories, follow these steps:

Convert kilowatt-hours to joules: $1 \text{ kWh} \times (3.6 \times 10^6) \frac{\text{J}}{\text{kWh}} = 3.6 \times 10^6 \text{ J}$
Convert joules to calories: $3.6 \times 10^6 \text{ J} \div 4.184 \frac{\text{J}}{\text{cal}} \approx 860420.66 \text{ cal}$

Therefore:

1 \text{ kWh} \approx 860420.66 \text{ cal}

Historical Context: James Prescott Joule

The unit of energy, the joule, is named after James Prescott Joule (1818-1889), a British physicist. Joule's most famous work involved establishing the relationship between heat and mechanical work, leading to the law of conservation of energy. He demonstrated that heat is a form of energy and that mechanical work could be converted into heat, and vice versa, in predictable ways. His experiments and measurements were crucial in the development of thermodynamics.

Real-world Examples

Food Energy to Electricity: A typical candy bar might contain 250 calories. Converting this to kilowatt-hours:
$250 \text{ cal} \times 1.1622 \times 10^{-6} \frac{\text{kWh}}{\text{cal}} \approx 0.00029 \text{ kWh}$
This is a tiny amount of electricity, barely enough to power a small LED bulb for a few minutes.
Exercise and Energy Consumption: A rigorous workout might burn 500 calories. Converting this to kilowatt-hours:
$500 \text{ cal} \times 1.1622 \times 10^{-6} \frac{\text{kWh}}{\text{cal}} \approx 0.00058 \text{ kWh}$
Still a small amount, but enough to run a small fan for a little while.
Home Appliance Energy: A microwave oven might use 1200 watts (1.2 kW). If you use it for 30 minutes (0.5 hours), the energy consumption in kWh is:
$1.2 \text{ kW} \times 0.5 \text{ hours} = 0.6 \text{ kWh}$
Converting this to calories:
$0.6 \text{ kWh} \times 860420.66 \frac{\text{cal}}{\text{kWh}} \approx 516252.4 \text{ cal}$
This illustrates the substantial energy usage of common household appliances compared to the energy in food.

Key Takeaways

Converting between calories and kilowatt-hours involves understanding the relationship between these units through joules.
The conversion factors are:
- $1 \text{ cal} \approx 1.1622 \times 10^{-6} \text{ kWh}$
- $1 \text{ kWh} \approx 860420.66 \text{ cal}$
Calories are typically used to measure the energy content of food, while kilowatt-hours are used to measure electrical energy consumption.

See below section for step by step unit conversion with formulas and explanations. Please refer to the table below for a list of all the Kilowatt-hours to other unit conversions.

What is calories?

Calories are a unit of energy, historically defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius. While the "calorie" is still commonly used, the kilocalorie (kcal), also known as the "large calorie" or "food calorie," is more prevalent when discussing dietary energy. In the International System of Units (SI), the joule (J) is the standard unit of energy.

Types of Calories

Small calorie (cal): The amount of energy required to raise the temperature of 1 gram of water by 1°C.
Large calorie (Cal) or Kilocalorie (kcal): The amount of energy required to raise the temperature of 1 kilogram of water by 1°C. This is the calorie commonly referred to in nutrition.

The relationship between these units is:

$1 \text{ Cal} = 1 \text{ kcal} = 1000 \text{ cal}$

Calorie to Joule Conversion

Since the joule is the SI unit for energy, it's useful to know the conversion factor:

$1 \text{ cal} \approx 4.184 \text{ J}$

$1 \text{ kcal} \approx 4184 \text{ J}$

Historical Context

While not directly related to a specific law, the development of calorimetry (the science of measuring heat) was crucial to understanding calories. Scientists like Nicolas Clément and later Wilbur Olin Atwater, a pioneer in nutrition science, contributed significantly to establishing calorie values for different foods. Atwater's work in the late 19th and early 20th centuries was instrumental in developing the calorie system used in nutrition today.

Real-World Examples and Calorie Values

Food:
- One medium apple (approx. 182g): ~95 kcal
- One slice of whole wheat bread: ~70 kcal
- A can of soda (355ml): ~150 kcal
Energy Expenditure:
- A 150-pound person running for 30 minutes at 6 mph burns approximately 340 kcal.
- Sleeping for 8 hours burns roughly 50 kcal per hour, totaling around 400 kcal.
Other Quantities:
- Gasoline: 1 gallon of gasoline contains approximately 31,000 kcal.

Measuring Calories in Food

Calories in food are typically determined using a bomb calorimeter. This device measures the heat released when a food sample is completely burned inside a closed chamber surrounded by water. The temperature increase of the water is then used to calculate the calorie content of the food. The caloric content in the three macronutrients are as follows:

Carbohydrates: 4 kcal/gram
Proteins: 4 kcal/gram
Fats: 9 kcal/gram

What is Kilowatt-hours?

Kilowatt-hours (kWh) is a unit of energy representing the amount of energy used by a 1-kilowatt (1000-watt) appliance operating for one hour. It's a standard unit for measuring electrical energy consumption.

Understanding Kilowatt-hours

Think of energy like water. Power is the rate at which water flows (like liters per second), and energy is the total amount of water that has flowed over a certain time. A kilowatt-hour is the amount of energy you get when you use power at a rate of one kilowatt for one hour.

The formula for calculating energy in kilowatt-hours is:

\text{Energy (kWh)} = \frac{\text{Power (Watts)} \times \text{Time (hours)}}{1000}

Formation of Kilowatt-hours

Kilowatt-hours are derived from the concepts of power and time. Power, measured in watts (W) or kilowatts (kW), represents the rate at which energy is used or produced. Time, measured in hours, indicates the duration of energy usage. Multiplying power (in kilowatts) by time (in hours) gives the energy consumed in kilowatt-hours.

Relevant Laws and Historical Context

While there isn't a specific "law" directly associated with kilowatt-hours, the concept is built upon the fundamental principles of energy and power in physics. These principles are governed by the laws of thermodynamics and electrical circuit theory.

James Watt: A Scottish inventor and mechanical engineer, is known for his improvements to the steam engine. The watt, the unit of power, is named in his honor. Understanding power is crucial to understanding kilowatt-hours.

Real-World Examples of Kilowatt-hour Consumption

Electric Stove: Running an electric stove that consumes 2 kW for 30 minutes (0.5 hours) uses 1 kWh of energy (2 kW x 0.5 h = 1 kWh).
Refrigerator: A refrigerator might use 50 watts (0.05 kW) continuously. Over 24 hours, it consumes 1.2 kWh (0.05 kW x 24 h = 1.2 kWh).
Television: Watching a 100-watt (0.1 kW) television for 10 hours consumes 1 kWh (0.1 kW x 10 h = 1 kWh).
Electric Vehicle (EV) Charging: Charging an electric vehicle might require 20 kWh to fully charge the battery, giving it a certain range.
Home Energy Usage: A typical household might consume 500 - 1000 kWh of electricity per month, depending on appliance usage, climate, and other factors.

Interesting Facts

Energy Bills: Kilowatt-hours are the standard unit used by utility companies to measure and bill electricity consumption.
Energy Efficiency: Understanding kWh consumption is crucial for assessing the energy efficiency of appliances and making informed decisions about energy usage.
Renewable Energy: Renewable energy sources like solar panels and wind turbines generate electricity measured in kilowatt-hours (or megawatt-hours for larger installations).

Complete calories conversion table

Enter # of calories

Convert 1 cal to other units	Result
calories to Watt-seconds (cal to Ws)	4.184
calories to Watt-minutes (cal to Wm)	0.06973333333333
calories to Watt-hours (cal to Wh)	0.001162222222222
calories to Milliwatt-hours (cal to mWh)	1.1622222222222
calories to Kilowatt-hours (cal to kWh)	0.000001162222222222
calories to Megawatt-hours (cal to MWh)	1.1622222222222e-9
calories to Gigawatt-hours (cal to GWh)	1.1622222222222e-12
calories to Joules (cal to J)	4.184
calories to Kilojoules (cal to kJ)	0.004184
calories to Megajoules (cal to MJ)	0.000004184
calories to Gigajoules (cal to GJ)	4.184e-9
calories to Kilocalories (cal to kcal)	0.001