Finding the right amount of miles to run each week when preparing for a marathon depends on how much running experience you have and how long you plan to train.

Here’s a simple guide:

• If you’re a beginner: Try to run about 15 to 20 miles each week.
• If you have some experience: Aim for 30 to 40 miles each week.
• If you’re very experienced: Run between 50 to 70 miles each week.

Most marathon training plans last about 16 to 20 weeks. During this time, you can increase your weekly mileage by around 10% each week.

Don’t forget to include rest days to help your body recover.

Also, make sure to plan for some long runs, which can go up to 20 miles.

In the last 2 to 3 weeks before the marathon, you should start to lower your running distance a bit. This is called tapering, and it helps you feel fresh and ready for race day!