**The answer is: it depends on what you are cooking and how often you use them. Generally, a combination microwave is more energy-efficient than a conventional oven, but not always cheaper to run.**

A combination microwave is a kitchen appliance that can function as both a microwave and a convection oven. It can cook food faster and more evenly than a regular oven, using less energy and saving space. But is it cheaper to run than a conventional oven? The answer is not so simple, as it depends on several factors, such as the type of food, the cooking time, the size of the appliance, and the electricity cost.

## Energy Efficiency of Combination Microwaves and Ovens

One way to compare the cost of running a combination microwave or an oven is to look at their energy efficiency. Energy efficiency is the ratio of useful output to input energy, measured in watts (W) or British thermal units (BTU). The higher the energy efficiency, the less energy is wasted and the lower the operating cost.

According to the U.S. Department of Energy, the average energy efficiency of a microwave oven is about 50%, meaning that half of the input energy is converted into useful output. The average energy efficiency of a gas oven is about 40%, while an electric oven is about 12%. This means that a microwave oven uses less energy than a gas or electric oven to produce the same amount of heat.

However, energy efficiency is not the only factor that affects the cost of running a combination microwave or an oven. Another factor is the cooking time. A combination microwave can cook food faster than a conventional oven, using the microwave function, the convection function, or both. For example, a combination microwave can bake a potato in about 15 minutes, while a conventional oven takes about an hour. This means that a combination microwave uses less energy per cooking cycle than a conventional oven.

## Cost Comparison of Combination Microwaves and Ovens

To compare the cost of running a combination microwave or an oven, we need to consider the energy consumption and the electricity price. Energy consumption is the amount of energy used by an appliance over a period of time, measured in kilowatt-hours (kWh) or therms. Electricity price is the amount of money charged for each unit of electricity, measured in cents per kWh or dollars per therm.

The energy consumption of a combination microwave or an oven depends on the power rating, the cooking time, and the frequency of use. The power rating is the maximum amount of energy that an appliance can draw, measured in watts (W) or BTU per hour. The cooking time is the duration of a cooking cycle, measured in minutes or hours. The frequency of use is the number of times an appliance is used per day, week, month, or year.

The electricity price of a combination microwave or an oven depends on the type of fuel, the location, and the time of use. The type of fuel is either electricity or natural gas, depending on the appliance. The location is the state or region where the appliance is used, which affects the electricity or gas rates. The time of use is the hour of the day or the season of the year when the appliance is used, which affects the electricity or gas demand and supply.

To calculate the cost of running a combination microwave or an oven, we need to multiply the energy consumption by the electricity price. For example, let’s assume that we have a combination microwave with a power rating of 1200 W and an electric oven with a power rating of 3000 W. Let’s also assume that we use them to cook the same food for the same time, once a day, for a year. Let’s also assume that the average electricity price in the U.S. is 13.3 cents per kWh.

The energy consumption of the combination microwave is:

1200 W x 15 minutes x 365 days / 1000 = 131.4 kWh

The energy consumption of the electric oven is:

3000 W x 60 minutes x 365 days / 1000 = 657 kWh

The cost of running the combination microwave is:

131.4 kWh x 13.3 cents = $17.48

The cost of running the electric oven is:

657 kWh x 13.3 cents = $87.38

Therefore, the combination microwave is cheaper to run than the electric oven by $69.90 per year.

However, this is not always the case. If we use the combination microwave or the oven for different foods, different times, or different frequencies, the cost comparison may change. For example, if we use the combination microwave to cook a large turkey for four hours, once a year, and the electric oven to reheat a slice of pizza for five minutes, once a week, the cost comparison may be different.

The energy consumption of the combination microwave is:

1200 W x 4 hours x 1 day / 1000 = 4.8 kWh

The energy consumption of the electric oven is:

3000 W x 5 minutes x 52 days / 1000 = 13 kWh

The cost of running the combination microwave is:

4.8 kWh x 13.3 cents = $0.64

The cost of running the electric oven is:

13 kWh x 13.3 cents = $1.73

Therefore, the combination microwave is cheaper to run than the electric oven by $1.09 per year.

## Conclusion

In conclusion, the answer to the question “Is it cheaper to run a combination microwave or oven?” is: it depends. A combination microwave is more energy-efficient than a conventional oven, but not always cheaper to run. The cost of running a combination microwave or an oven depends on several factors, such as the type of food, the cooking time, the size of the appliance, the electricity cost, and the frequency of use. Therefore, the best way to save money and energy is to use the combination microwave or the oven wisely, according to the specific cooking needs and preferences.