How Long Does It Take To Preheat an Oven to 400, 425, 450?

Preheating your oven before adding those made-from-scratch cookies is an essential tactic for producing the perfect cookie.

If you fail to preheat the oven, you can run into issues as the cookies may bake unevenly or take an extended period to cook. The necessary time to preheat an oven changes for several reasons, but the average time to preheat an oven is typically between 11 and 25 minutes. 

So let’s get you an answer to the question – how long does it take to preheat an oven to 400 and which factors to consider?

How an Oven Heats Up

It probably won’t come as a surprise to hear that conventional household ovens heat up by generating heat energy, which is distributed throughout its interior to cook food. However, the methods used to generate the heat  and distribute it differs depending on whether the oven is electric, fan-assisted, or gas-operated. So when we look to understand how long it takes to preheat your oven it will very based on the heating technology it uses.

Electric Oven

Electric ovens use electricity to heat up elements usually positioned at the top and the bottom of the oven. As the elements heat up, they gradually warm the air inside the oven chamber. This type of heat is static, and as such can result in hot spots, with the hottest point often being located toward the top of the oven or next to the heating elements.

Fan Assisted Oven

A fan-assisted oven uses the same electrically heated elements, as mentioned previously. But they also include a fan at the back of the oven, that helps to circulate the hot air throughout the oven, creating an even temperature.

Gas Oven

In a gas oven, gas flows into a burner tube where can mix with air and gets ignited by a pilot light. It is this flame that gradually heats the air inside the oven. It most situations gas ovens heat up faster than electric ovens, but the heat distribution is typically less even than an electric or fan-assisted oven.

You may also be interested in Why Your Oven Smells Like Gas When Preheating

Gas vs. Electric Oven Preheat Times

Gas ignites instantly and produces a significant amount of heat straight away. This ‘immediate availability’ of heat from the flaming burners usually results in gas ovens reaching temperature the required temperature in less time than electric ovens. If you image the heating element in an electric oven will slowly warm before it reaches a comparable temperature of the gas burner.  

How Long To Preheat an Oven

The average time for an oven to preheat will vary significantly based on a number of variables, such as its type (gas, electric, fan-assisted), its size, age, cleanliness, and how well it’s insulated. That being said I can give you some general estimates:

Gas Ovens

Gas ovens heat faster than electric and fan assisted ovens. In fact they can preheat to a range between 400-450 degrees in around 7 to 10 minutes. The instant heat produced by the gas burner gives this oven type a distinct advantage over electric ovens.

Fan-assisted Electric Ovens

The fan-assisted electric ovens is the next most effective oven for preheating. They take between 8 to 10 minutes to preheat to 400 to 450 degrees. The fan located at the back of the oven speeds up preheating time, and ensures even heat distribution.

Electric Ovens

Acknowledging that electric ovens take longer to preheat compared to gas ovens. They might take anywhere from 10 to 15 minutes to preheat to 400 to 450 degrees. The heating element needs to warm up and then the oven chamber will create hot spots that need to flatten out as the whole oven warms. This makes electric ovens the slowest oven type with regards to preheating.  

These timing are estimates based on averages, your oven may take more or less time depending on its specification and a number of other factors that we will discuss later.

Quick Reference Oven Preheating Times

Here are the estimated times to preheat an oven to certain common cooking temperatures:

Electric Ovens

To 350°F (175°C): 10-15 minutes

To 375°F (190°C): 12-18 minutes

To 400°F (205°C): 13-20 minutes

To 425°F (220°C): 14-21 minutes

To 450°F (230°C): 15-23 minutes

To 475°F (245°C): 16-25 minutes

To 500°F (260°C): 17-27 minutes

Fan-assisted Electric Ovens

To 350°F (175°C): 8-12 minutes

To 375°F (190°C): 9-14 minutes

To 400°F (205°C): 10-15 minutes

To 425°F (220°C): 11-16 minutes

To 450°F (230°C): 12-17 minutes

To 475°F (245°C): 13-18 minutes

To 500°F (260°C): 14-20 minutes

Gas Ovens

To 350°F (175°C): 7-10 minutes

To 375°F (190°C): 8-11 minutes

To 400°F (205°C): 9-12 minutes

To 425°F (220°C): 10-13 minutes

To 450°F (230°C): 11-14 minutes

To 475°F (245°C): 12-15 minutes

To 500°F (260°C): 13-16 minutes

Steps To Preheating an Oven

Getting your oven ready for optimal cooking is a relatively easy task but does require several steps. When preheating an oven, ensure you set it to the correct temperature and wait until it reaches that temperature before adding the food.

Step 1: Remove any unnecessary items from the oven.

When heating an oven to a specific temperature each item within it also need to be heating up to that exact temperature. So this means if you leave roasting tins, additional unrequired oven racks in the oven it will increase the time it takes to reach temperature. So remove all unnecessary equipment if you wish to reach the required preheat temperature efficiently.

Step 2: Set the temperature.

Confirm whether you preheat temperature is in Celsius or Fahrenheit and set the temperature. If you are following a receipt of require the oven to be at temperature at a certain time, then I recommend leaving an extra 5 minutes, to override any external factors that may influence the preheat time. Avoid opening the oven during preheating, as this will let the hot air escape and extend the heating time.

Step 3: Wait for the oven to preheat.

Most modern ovens have an indicator to signal when they’ve reached the required temperature. Some oven have a light that either comes on or goes out, whilst some will beep.

If your oven doesn’t have a built in signal, you use the estimated preheat times provided earlier in this article. An oven thermometer can also be a huge help if oven temperature is critical to your recipe.

Step 4: Place your food in the oven.

Once the oven has preheated, open the oven door and position the food. For standard electric ovens remember the top shelf if often the hottest and the bottom shelf the coolest.

Step 5: Cooling before cooking

Bear in mind if you have preheated you oven to a certain temperature and then place a big roast joint from the fridge into the oven, the oven temperature will temporarily drop and the heat indicator light may come back on. Don’t worry, it will soon heat up, and the cooking times that you are following will have accounted for this.

How To Know When the Oven Is Preheated 

We have covered most elements of preheating your oven on the basis that most homes will be fitted with a modern oven that has a temperature indicator light or beeper. But it’s often the case that many of us have yet to figure out how to get our ovens control panel functions to work, or perhaps your oven simply doesn’t have an indicator feature. So just in case, here’s how you can determine if your oven is ready:

1. Built-in Oven Thermometer

Some ovens have a built-in thermometer located inside the oven on the side wall. This gauge will displays the temperature inside the oven and is a useful reference point. Bear in mind that the accuracy of these built-in thermometers can vary and each time you open the oven door to read it you are loosing heat. So check it infrequently.

2. Separate Oven Thermometer

Buy a separate oven thermometer, that you can placed inside the oven where you can see it without opening the oven door. This type of thermometer will often provide a more accurate reading of the oven’s temperature.

3. Observation

If your oven doesn’t have an indicator light or a thermometer, you can use the estimated heating times I provided earlier in this article. In general, most ovens will take between 10-15 minutes to preheat between 350-400 degrees Fahrenheit.

FAQ’s Preheating an Oven

While preheating an oven is generally an easy task, there are plenty of questions that may arise when performing the preheating cycle. 

Why do we preheat the oven?

Preheating an oven is vital to the way the food cooks. If you do not preheat the oven before using it, you run the risk of your food cooking unevenly or not at all. Baked goods might burn on the edges while the center remains uncooked.

Are 10 minutes enough to preheat an oven?

The size, type of oven, preset temperature, and age of the oven are all factors that contribute to the preheating cycle. In general, 10 minutes is enough to preheat a gas oven to 200 – 350 degrees Fahrenheit or an electric oven to 180 – 300 degrees Fahrenheit. 

Preheating an Oven to 400 degrees or More

So, how long does it take to preheat an oven to 400 degrees? It depends on various factors. Although preheating an oven to 400 degrees Fahrenheit or higher usually takes some time, it will ensure that your food cooks evenly. Plan to wait anywhere from 11 to 25 minutes to allow your oven to fully preheat before use.