Is It Cheaper to Use a Microwave or Oven?

Information current as of 11/2023.

A microwave is often the lower-energy choice for small portions, reheating, and short cooking tasks because it avoids much of a full-size oven’s preheating and cavity-heating period. An oven may be the better choice for large quantities, baking, roasting, crisping, or browning. There is no universal dollar answer: compare each appliance’s actual energy input, complete operating time, food quantity, and local utility rate.

Microwave or oven: which is usually cheaper?

For a single serving, leftovers, or another small and short task, a microwave often uses less energy than heating a full-size conventional oven. The advantage comes partly from avoiding the oven’s longer warm-up and cavity-heating period. This is a general direction, not a guarantee for every appliance, food, or cooking method.

When an oven can be the better choice

An oven can be more practical when you are preparing a large quantity or several portions in one cooking cycle. It is also the appropriate choice when the result depends on dry surrounding heat, such as baking, roasting, browning, or crisping. For these tasks, the comparison should include the amount of food prepared and the required texture, not just the appliance’s rated power.

How to compare the energy cost

Compare complete cooking cycles rather than looking only at the time when food is actively cooking. For an electric appliance, estimate consumption as: consumption in kWh = actual input power in kW × operating time in hours. Then estimate electricity cost as: consumption in kWh × your electricity price in dollars per kWh. Include oven preheating and any idle or holding time. For a gas oven, use its gas input and applicable gas rate instead of treating it like an electric oven.

A practical decision rule

Choose the microwave first for reheating, one small portion, or a short task when its cooking result is suitable. Choose the oven for large batches or foods that need browning, crisping, roasting, or baking. Treat a convection microwave separately from a microwave-only oven because its convection or thermal mode changes the heating method and comparison.

Important details that can change the result

Microwave performance varies with the model, power level, container, food density, and whether food is covered or stirred. A microwave can also use some electricity while idle through its controls and display. Conversely, an oven’s total use can include preheating and holding energy; for some foods and conditions, skipping preheating may use less energy, but whether preheating is appropriate depends on the recipe and appliance instructions.