Temperature Unit

Original Cooking Time

Hours

Minutes

Using a fan / convection oven

Applies an additional 20% reduction to account for faster convection cooking

Adjusted Cooking Time

Check for doneness 5-10 minutes before the calculated time. All ovens vary - use a thermometer for best accuracy.

Formula

Adjusted Time = Original Time × (Original Temp ÷ New Temp)

This formula is based on the principle that cooking time is inversely proportional to oven temperature: a higher temperature means less time needed. This is a practical approximation used in culinary guides - actual results vary by food type, thickness, and oven calibration.

For convection ovens, an additional 20% reduction is applied to account for the faster heat transfer from circulated air.

Examples

Recipe calls for 180°C for 60 min, oven only goes to 200°C

60 × (180 ÷ 200) = 60 × 0.9 = 54 minutes

Result: ~54 minutes

Slow cook at 160°C for 90 min → switch to 180°C

90 × (160 ÷ 180) = 90 × 0.889 = 80 minutes

Result: ~80 minutes

FAQ

This is a practical approximation - it works well for most roasted meats, casseroles, and baked goods. Very dense items (like a large roast) or delicate items (like soufflés) may need more careful monitoring. Always check for doneness before relying solely on the calculated time.

Large temperature changes (over 30-40°C) affect browning and moisture loss non-linearly. For significant changes, start checking doneness 15-20% before the calculated end time. Use a meat thermometer for proteins.

Pro Tip

Always check for doneness 5-10 minutes before the calculated end time. The formula gives an estimate - oven calibration, food density, and starting temperature all affect actual results.