Fan Oven to Air Fryer Conversion — The Complete UK Guide
Convert your fan oven recipes to air fryer settings with our comprehensive guide. Includes Celsius temperature charts, Gas Mark conversions, and cooking times for popular UK foods.
Fan oven to air fryer conversion: Reduce the fan oven temperature by 20°C and reduce the cooking time by 15-20%. Fan ovens already circulate heat, so the gap between a fan oven and an air fryer is smaller than from a conventional oven. For example, a recipe at 200°C fan becomes 180°C in the air fryer.
What Is a Fan Oven?
A fan oven (also called a convection oven) has a built-in fan that circulates hot air around the food. This results in more even cooking and faster cooking times compared to a conventional oven where heat simply rises from the bottom or top elements.
In the UK, most modern ovens are fan-assisted. Recipes often specify "fan" temperatures, which are typically 20°C lower than conventional oven temperatures. When converting to an air fryer, you're starting from this already-reduced temperature.
Fan Oven vs Conventional Oven vs Air Fryer
| Feature | Conventional Oven | Fan Oven | Air Fryer |
|---|---|---|---|
| Cooking Method | Still air, heat rises | Circulating hot air | Rapid air circulation |
| Cooking Speed | Slowest | 20-25% faster | Fastest (20% faster than fan) |
| Temperature | Full recipe temp | Reduce by 20°C | Reduce by 20°C from fan |
| Capacity | Large (multiple trays) | Large (multiple trays) | Small (single basket) |
| Preheating | 10-15 min | 10-15 min | 3-5 min |
| Energy Use | Highest | Medium | Lowest |
Fan Oven to Air Fryer Temperature Chart (°C)
| Conventional Oven | Fan Oven | Air Fryer |
|---|---|---|
| 140°C | 120°C | 100°C |
| 150°C | 130°C | 110°C |
| 160°C | 140°C | 120°C |
| 170°C | 150°C | 130°C |
| 180°C | 160°C | 140°C |
| 190°C | 170°C | 150°C |
| 200°C | 180°C | 160°C |
| 210°C | 190°C | 170°C |
| 220°C | 200°C | 180°C |
| 230°C | 210°C | 190°C |
| 240°C | 220°C | 200°C |
Gas Mark to Air Fryer Conversion
If your recipe uses Gas Marks, use this table to find the equivalent air fryer temperature.
| Gas Mark | Conventional °C | Fan Oven °C | Air Fryer °C |
|---|---|---|---|
| 1 | 140°C | 120°C | 100°C |
| 2 | 150°C | 130°C | 110°C |
| 3 | 170°C | 150°C | 130°C |
| 4 | 180°C | 160°C | 140°C |
| 5 | 190°C | 170°C | 150°C |
| 6 | 200°C | 180°C | 160°C |
| 7 | 220°C | 200°C | 180°C |
| 8 | 230°C | 210°C | 190°C |
| 9 | 240°C | 220°C | 200°C |
Fan Oven to Air Fryer Cooking Time Chart
| Fan Oven Time | Air Fryer Time | Time Saved |
|---|---|---|
| 10 min | 8 min | -2 min |
| 15 min | 12 min | -3 min |
| 20 min | 16 min | -4 min |
| 25 min | 20 min | -5 min |
| 30 min | 24 min | -6 min |
| 40 min | 32 min | -8 min |
| 50 min | 40 min | -10 min |
| 60 min | 48 min | -12 min |
Step-by-Step: How to Convert Fan Oven Recipes
Step 1 — Identify the fan oven temperature
Check if your recipe specifies "fan" or "fan oven" temperature. If it only gives a conventional temperature, reduce it by 20°C to get the fan equivalent first.
Step 2 — Reduce the temperature by 20°C
Subtract 20°C from the fan oven temperature to get your air fryer setting. For example, 200°C fan becomes 180°C in the air fryer.
Step 3 — Reduce the time by 15-20%
Multiply the fan oven cooking time by 0.80-0.85 to get the air fryer time. For a 30-minute recipe, that's 24-26 minutes in the air fryer.
Step 4 — Check early and adjust
Start checking at 75% of the calculated time. Air fryer models vary, so your first attempt helps you calibrate for future cooking.
Common UK Foods — Air Fryer Conversion
| Food | Fan Oven | Air Fryer | Notes |
|---|---|---|---|
| Chips (frozen) | 200°C, 20-25 min | 180°C, 15-18 min | Shake halfway |
| Jacket Potato | 200°C, 60-75 min | 180°C, 45-55 min | Poke holes, rub oil |
| Sausage Rolls | 200°C, 20-25 min | 180°C, 15-20 min | Check pastry is golden |
| Fish Fingers | 200°C, 15-20 min | 180°C, 10-12 min | Turn halfway |
| Roast Chicken (whole) | 180°C, 75-90 min | 160°C, 55-70 min | Use rotisserie if available |
| Yorkshire Puddings | 220°C, 20-25 min | 200°C, 12-15 min | Don't open during cooking |
| Shepherd's Pie | 180°C, 25-30 min | 160°C, 20-25 min | Use oven-safe dish |
| Pasty / Pasty | 180°C, 25-30 min | 160°C, 18-22 min | Check pastry is cooked |
| Bacon | 180°C, 15-20 min | 160°C, 8-12 min | Single layer |
| Bangers (sausages) | 200°C, 20-25 min | 180°C, 15-18 min | Turn occasionally |
Energy Savings: Air Fryer vs Fan Oven
With UK energy costs at approximately 24-30p per kWh (2026), air fryers offer significant savings for small to medium portions:
- •Air fryer (1,500W, 20 min): ~0.5 kWh = 12-15p
- •Fan oven (2,500W, 45 min): ~1.9 kWh = 45-57p
- •Savings per meal: 30-45p (for small portions)
Note: For large family meals or multiple items, a fan oven may still be more efficient as you can cook more at once.
Tips for UK Air Fryer Users
- •Check your air fryer's capacity: UK air fryers are often measured in litres. A 5-6 litre model suits most families.
- •Popular UK brands: Ninja, Tower, Tefal, and Cosori are widely available. Ninja tends to run slightly hotter.
- •Chip shop style chips: Par-boil chips for 5-6 minutes, dry thoroughly, coat in oil, then air fry at 180°C for 15-18 min.
- •For frozen chips: Most UK frozen chips cook perfectly at 180°C for 15-18 minutes. Shake halfway.
- •Use the calculator: Our air fryer converter handles both °C and °F.
Frequently Asked Questions
What's the rule for converting fan oven to air fryer?
Reduce the fan oven temperature by 20°C and the cooking time by 15-20%. Fan ovens already use circulating hot air, so the adjustment from fan oven to air fryer is smaller than from a conventional oven.
Is a fan oven the same as a convection oven?
Yes, "fan oven" is the UK term for what Americans call a "convection oven." Both have a fan that circulates hot air for more even and faster cooking compared to conventional ovens.
Do I need to convert differently for a fan oven vs regular oven?
Yes. Converting from a conventional (non-fan) oven requires a larger adjustment: reduce temperature by 25°C and time by 20%. Converting from a fan oven requires a smaller adjustment: reduce by 20°C and 15-20% time.
What Gas Mark corresponds to 180°C in the air fryer?
180°C in the air fryer corresponds to Gas Mark 4 on a conventional oven, or Gas Mark 5 on a fan oven setting. Use our Gas Mark conversion table above for exact conversions.
Is an air fryer cheaper to run than a fan oven?
Yes, an air fryer is typically cheaper to run. A standard air fryer uses 1,400-1,800 watts for 15-30 minutes, while a fan oven uses 2,000-3,000 watts for 30-60+ minutes. For small portions, an air fryer can use 50-70% less energy.
Can I convert slow cooker recipes to air fryer?
Slow cooker recipes require different conversion logic since they use low, moist heat over many hours. Air fryers cook quickly with dry heat. Generally, you'll need to increase the temperature significantly and reduce time by 80-90%. It's often easier to find a specific air fryer version of the recipe.
Related Resources
- Air Fryer Conversion Calculator — Convert any recipe instantly
- Complete Conversion Chart — Printable temperature and time tables
- Cooking Times Chart — 40+ foods with detailed instructions
- Best Air Fryers UK — Top picks for British kitchens