The preheating time for an oven can vary depending on the type of oven and the desired cooking temperature. In general, electric ovens tend to preheat faster than gas ovens. As a general guideline:
Standard electric oven: Preheat for about 10 to 15 minutes to reach temperatures around 350°F to 375°F (175°C to 190°C).
Standard gas oven: Preheat for about 15 to 20 minutes to reach temperatures around 350°F to 375°F (175°C to 190°C).
High-temperature cooking (e.g., 450°F/230°C or higher): Preheat for about 20 to 25 minutes to allow the oven to reach the higher temperature.
Keep in mind that some modern ovens come with a preheat indicator that tells you when the desired temperature is reached. Additionally, if you're using a convection oven, it may require slightly less preheating time compared to conventional ovens.
Always refer to your oven's user manual for specific preheating instructions and temperature recommendations, as the times and temperatures can differ from model to model. Preheating is essential to ensure that your recipes cook evenly and accurately, especially for baked goods and delicate dishes.