# Microwave vs Oven: 2026 UK Cost Comparison
Updated: May 2026 — Power Guardian UK Editorial Team
A fan oven sucks up serious electricity. A microwave doesn't. If you reheat or cook small portions in the oven, you're throwing away £40–£100 a year.
Cost per use at 27p/kWh
| Appliance | Power | Time | Energy | Cost per use |
|---|---|---|---|---|
| Microwave (800W) | 0.8 kW | 5 min | 0.07 kWh | 1.8p |
| Microwave (800W) | 0.8 kW | 10 min | 0.13 kWh | 3.6p |
| Fan oven (preheat + cook) | 2.0 kW | 30 min | 1.0 kWh | 27p |
| Fan oven (1hr roast) | 2.0 kW | 60 min | 2.0 kWh | 54p |
| Combi microwave/oven | 1.4 kW | 20 min | 0.47 kWh | 12.6p |
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The headline number
A microwave uses about 1/15th of the energy of a fan oven for reheating a single portion. Use it for leftovers, ready meals, jacket potatoes (start in microwave, finish in oven for crisp skin) and steaming veg.
When the oven still wins
- Cooking 4+ portions at once — efficiency per person improves
- Roasts, baking, anything needing browning
- Batch cooking on a Sunday for the week
Quick-win swaps
- Reheating one plate: microwave, not oven
- Jacket potato: microwave 8 min, oven 10 min (vs 75 min oven only) — saves 21p per spud
- Frozen pizza for one: air fryer or grill, not full oven
- Steaming veg: microwave with 2 tbsp water, lidded — uses ~1.5p of energy
What this saves a typical UK home
If you currently use the oven 4 times a week for small portions and switch half of those to the microwave: £45–£70/year off your electricity bill.
Check My Bill
Cooking habits matter — but the biggest energy savings usually come from your tariff, not your appliances.
Use our free Bill Checker to see in 30 seconds — most users find savings of £200–£500 per year.
Is it really cheaper to use a microwave than an oven in the UK?
Yes, a microwave is significantly cheaper to run. Reheating a single portion costs around 1.8p in a microwave compared to 27p in a fan oven at 27p/kWh. This means a microwave uses about 1/15th of the energy of an oven for small tasks.
How much money can I save by switching from oven to microwave?
A typical UK home could save £45–£70 per year by switching just half of their small portion oven uses (4 times a week) to the microwave. This is a substantial saving on electricity bills.
Recommended Smart Energy Plug
Monitor appliance electricity usage in real time and identify expensive devices around your home.
View on Amazon UKWhen is it still better to use an oven over a microwave?
The oven still wins for cooking four or more portions at once, as its efficiency per person improves. It's also essential for roasts, baking, and anything needing browning, or for batch cooking.
Can I cook a jacket potato in the microwave to save energy?
Yes, you can significantly save energy by starting a jacket potato in the microwave for 8 minutes, then finishing it in the oven for 10 minutes. This method saves approximately 21p per potato compared to cooking it entirely in the oven.
Are there other quick energy-saving swaps for cooking beyond just microwave vs oven?
Yes, for a frozen pizza for one, an air fryer or grill is more energy-efficient than using a full oven. Also, steaming vegetables in the microwave with two tablespoons of water uses only about 1.5p of energy, making it a very economical choice.
Recommended kit
Ninja Foodi Dual Zone Air Fryer
Cooks most meals at a fraction of the kWh of a full oven — typical savings of £100+/year for daily users.
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