The short answer is yes: running an oven costs significantly more than running a microwave in the UK. According to the Energy Saving Trust, a typical electric oven uses around 2.0–2.2 kWh per hour of use, while a microwave uses approximately 0.7–1.2 kWh per hour (Energy Saving Trust, 2026). At the current average electricity rate of 28p per kWh (Ofgem price cap), an oven costs roughly 56–62p per hour, compared to a microwave at 20–34p per hour.
The key variable is cooking time. A microwave heats food in minutes, whereas an oven often runs for 30–60 minutes or longer. For a typical 20-minute microwave meal, the cost is about 9–11p. For a 45-minute oven bake, the cost jumps to 42–47p. This difference becomes more pronounced with larger meals or batch cooking.
Energy efficiency comparison between oven and microwave
Microwaves are inherently more energy-efficient because they directly heat the water molecules in food, wasting very little heat to the surrounding air. The Energy Saving Trust notes that microwaves are around 60–70% efficient at converting electricity into heat for food, compared to conventional ovens at 10–20% efficiency (Energy Saving Trust, 2026). Ovens heat a large cavity and lose energy through walls and door seals. A microwave also heats only the food, not the entire appliance interior, so less energy is wasted.
Typical running costs for oven vs microwave in 2026
Based on the current UK average electricity price of 28p per kWh (set by Ofgem’s price cap), a standard electric oven (2.0 kW) costs about 56p per hour of use (Ofgem, 2026). A microwave (0.8 kW) costs around 22p per hour. For a 30-minute cooking session, the oven costs 28p, while the microwave costs 11p. Over a year, if you use the oven for 200 hours and the microwave for 100 hours, the oven costs £112 compared to £22 for the microwave. This gap widens with higher-wattage ovens or longer cooking times.
When a microwave is cheaper than an oven for cooking
A microwave is almost always cheaper for reheating leftovers, defrosting, or cooking small portions. However, for tasks requiring browning, crisping, or even heating (like roasting meat or baking cakes), a microwave cannot substitute an oven. The Energy Saving Trust advises using a microwave for vegetables, pasta, and rice to save up to 50% on cooking energy compared to an oven (Energy Saving Trust, 2026). For larger meals, consider using a slow cooker or air fryer, which can be cheaper than an oven but still more expensive than a microwave per use.
A worked example
For a typical 1930s semi-detached home in Manchester cooking a Sunday roast, the oven costs £1.68 per use compared to a microwave at 34p for a similar-sized ready meal. A family in a three-bedroom semi uses an electric oven for 90 minutes at 2.1 kWh, costing 59p per hour or 89p total at the current 28p per kWh rate (Ofgem price cap). The microwave runs for 15 minutes at 0.9 kWh, costing just 25p per hour or 6p total. Over a year of weekly roasts, the oven adds £46 to the electricity bill versus £3 for the microwave, a saving of £43 annually. The upfront cost of a microwave is around £80, so it pays for itself in less than two years of oven replacements. Check the Energy Saving Trust for tailored calculations based on your appliance wattage.
| Item | Figure |
|---|---|
| Upfront cost after grants | £80 (microwave) vs £400 (oven) |
| Yearly savings | £43 |
| Payback period | 1.9 years |
| 25-year lifetime savings | £1,075 |
What homeowners often get wrong
The most common mistake is assuming the oven’s higher wattage always means higher costs per use, ignoring cooking time differences. This leads to overestimating microwave savings or underestimating oven bills. Here are three specific errors to avoid
- Comparing wattage without time A 2,200W oven running for 10 minutes uses 0.37 kWh, costing 10p, while a 900W microwave running for 10 minutes uses 0.15 kWh, costing 4p. The mistake is thinking wattage alone determines cost. The right approach is to multiply wattage by hours of use. Ignoring time can make an oven seem cheaper than it is for longer bakes.
- Forgetting the oven preheat cost Many homeowners calculate only the cooking time, missing the 10–15 minute preheat that adds 5–8p to every oven use. This oversight means actual oven costs are 10–15% higher than estimated. For a weekly roast, that’s an extra £4 per year wasted on unaccounted energy.
- Believing all microwaves are equal Older microwaves (pre-2010) are often only 40–50% efficient, costing up to 50p per hour, while modern inverter models hit 70% efficiency at 28p per hour. The mistake is using a low-efficiency microwave and assuming it’s always cheaper than an oven. Check the Energy Saving Trust for efficiency ratings before buying.
Quick reference
- A typical electric oven uses 2.0–2.2 kWh per hour, costing 56–62p at the current 28p per kWh rate.
- A microwave uses 0.7–1.2 kWh per hour, costing 20–34p. That makes it roughly 50–60% cheaper per hour of use.
- Microwaves are 60–70% efficient at converting electricity into food heat, whereas ovens are only 10–20% efficient.
- A 20-minute microwave meal costs 9–11p, while a 45-minute oven bake costs 42–47p, a difference of 31–38p per use.
- Always check your appliance’s exact wattage on the rating plate, as older models can be significantly less efficient.
Frequently Asked Questions
At the current Ofgem price cap of 28p per kWh, a typical electric oven costs 56–62p per hour of use, based on Energy Saving Trust data.
A microwave costs 20–34p per hour at the 28p/kWh rate, according to the Energy Saving Trust. Actual cost depends on wattage and cooking time.
Yes, a microwave is significantly cheaper. For a 20-minute meal, a microwave costs 9–11p, while a 45-minute oven bake costs 42–47p, per Energy Saving Trust figures.
