For most reheating tasks, a microwave uses less energy than a toaster oven. However, for cooking or browning foods, a toaster oven can be more efficient than a full-size oven, and its energy draw depends on cooking time and temperature. The right choice depends on what you’re making.

Quick Answer

Toaster ovens and microwaves differ in how they heat food and their energy consumption. A microwave uses electromagnetic waves to heat water molecules directly, making it fast and efficient for small portions. A toaster oven uses electric resistance coils to heat the air inside, which takes longer and uses more energy per minute, but it can cook foods that a microwave cannot brown or crisp.

  • Microwave efficiency: Microwaves are typically more energy-efficient for reheating and defrosting because they heat food directly, reducing energy loss. They use about 1,000–1,200 watts and cook in minutes.
  • Toaster oven efficiency: Toaster ovens use 1,200–1,800 watts and take longer to preheat and cook, but for small batches, they use less energy than a conventional oven. They excel at browning and crisping.
  • Standby power: Both appliances draw a small amount of power when plugged in but not in use (vampire power). Unplugging or using a smart strip can save minor energy.
  • Task-based comparison: For a single slice of pizza, a microwave uses about 0.05 kWh, while a toaster oven uses 0.1–0.2 kWh. For baking cookies, a toaster oven uses less energy than a full oven.

How Microwaves Use Energy

Microwaves generate electromagnetic waves that agitate water molecules in food, producing heat. This direct heating means little energy is wasted heating the air or the appliance walls. Most countertop microwaves are rated between 700 and 1,200 watts. A typical reheating session lasts 1–3 minutes, consuming roughly 0.02 to 0.06 kilowatt-hours (kWh).

Because microwaves cook quickly, they are often the most energy-efficient choice for small portions and tasks like melting butter, reheating leftovers, or defrosting. However, they cannot brown or crisp food, which limits their usefulness for certain dishes.

How Toaster Ovens Use Energy

Toaster ovens use electric heating elements to warm the air inside an insulated cavity. They typically draw 1,200 to 1,800 watts and require a preheat period of 3–5 minutes. For a 10-minute cooking cycle, a toaster oven might use 0.2 to 0.3 kWh, which is more than a microwave for the same volume of food.

Yet, for tasks like baking a small casserole, roasting vegetables, or reheating pizza with a crispy crust, a toaster oven is far more efficient than heating a full-size oven. It also provides even browning and texture that a microwave cannot achieve.

Energy Comparison for Common Tasks

  • Reheating a single plate of leftovers: Microwave uses about 0.05 kWh; toaster oven uses 0.15–0.25 kWh (including preheat).
  • Baking 4 cookies: Toaster oven uses ~0.2 kWh; full-size oven uses ~0.5–0.7 kWh. Microwave cannot bake cookies.
  • Defrosting 1 lb of ground beef: Microwave uses ~0.08 kWh in 6 minutes; toaster oven would take 20+ minutes and use ~0.4 kWh.
  • Toasting 2 slices of bread: Toaster oven uses ~0.1 kWh for 5 minutes; microwave cannot toast bread (it becomes soggy).

Which Appliance Should You Choose?

If your primary goal is to reheat leftovers, defrost frozen foods, or warm beverages, a microwave is the more energy-efficient choice. It finishes tasks quickly and uses less electricity per use.

If you frequently cook or reheat foods that benefit from browning, crisping, or baking—like pizza, roasted vegetables, or small batches of baked goods—a toaster oven is better. Despite higher per-minute energy use, it avoids the waste of heating a large oven and delivers superior texture.

Many households own both appliances and use them strategically: microwave for speed, toaster oven for quality. Consider your cooking habits to decide which one to use for each task.

Tips to Reduce Energy Waste with Either Appliance

  • Use the microwave’s lower power settings for defrosting to avoid overheating food and wasting energy.
  • Preheat the toaster oven only when necessary; for small items like toast or frozen snacks, skip preheat and add a minute or two to cook time.
  • Cook multiple items at once in the toaster oven to make the most of the heated cavity.
  • Unplug both appliances when not in use, or connect them to a power strip that you switch off, to eliminate standby power draw.

Pro Tips

  • To save energy when reheating a single item, choose the microwave; for multiple items or crisp results, use the toaster oven and batch them together.
  • Use the microwave’s built-in sensor or auto-cook functions to avoid overcooking and wasting energy.
  • For toaster ovens, position food closer to the heating elements to reduce cook time and energy use.
  • Clean the microwave and toaster oven regularly; food buildup can cause longer cooking times and higher energy consumption.

Common Mistakes to Avoid

  • Using the toaster oven to reheat small amounts of food that could be done in the microwave in half the time.
  • Preheating the toaster oven for items that don’t need it, like frozen waffles or leftover pizza.
  • Running the microwave empty, which can damage the appliance and waste energy.
  • Leaving either appliance plugged in when not in use for extended periods, adding to standby energy waste.

FAQ

Does a toaster oven use more electricity than a microwave?

Generally, yes, for the same task. A microwave uses less energy per minute and finishes faster. However, for baking or browning, a toaster oven is more efficient than a full-size oven.

Can I replace my microwave with a toaster oven?

Not entirely. A toaster oven cannot match the speed of a microwave for reheating liquids or defrosting. If you cook often and value texture, you might prefer a toaster oven, but you’ll miss the convenience of a microwave for quick tasks.

Which appliance is cheaper to run over a year?

It depends on usage. If you mostly reheat leftovers, the microwave will cost less. If you bake small items frequently, the toaster oven may be more economical than using a conventional oven. A mix of both gives the best balance.

The Bottom Line

Choosing between a toaster oven and microwave for energy efficiency comes down to what you cook most. For quick reheats, the microwave wins. For crispy, browned results, the toaster oven is better than a full oven. Use each appliance for its strengths to save both energy and time.

Related Guides