Fan oven (convection) vs Conventional oven
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
Roasting vegetables, cooking multiple trays simultaneously, anything where even browning matters.
Delicate sponge cakes, choux pastry, egg custards — where circulating air can over-brown the top before the inside sets.
| Aspect | Fan oven (convection) | Conventional oven |
|---|---|---|
| Air movement | Fan circulates | Still air |
| Temperature evenness | Very even | Hot spots (top hotter) |
| Conversion rule | Set 20°C lower than conventional | Standard temperature |
| Best for | Roasting, multiple dishes | Delicate bakes |
| Browning | Even | Lighter top required for delicate items |
Frequently asked
Why do fan oven cakes sometimes sink?
The moving air can set the crust before the centre rises, creating a dome that then collapses. For light cakes, use conventional heat (no fan) for the first 20 minutes, then switch to fan or turn off if the top is browning fast.
Can I use fan and grill together?
Yes — many UK ovens have a 'fan with grill' setting that gives the speed of fan cooking with the browning of grill heat. Useful for finishing gratins and roasts. Don't confuse with 'full grill' which is top-element-only at high heat.