You wake up in the morning, you’re feeling great and you step on the scale. Within seconds your entire day is changed—if the number is what you want to see, you feel amazing and move through your day with great pride. If it’s not what you want to see, however, the day can take a spiraling turn for the worst right away.

This is why it’s important to know when to weigh yourself. Your body is always fluctuating and that two extra pounds could have nothing to do with the extra slice of cake you ate the night before: “This is because of body fluid fluctuations—you might be retaining water from too much sodium consumption, or you may not have gone to the bathroom yet,” according to JillianMichaels.com.

So how often should you weigh yourself? The general consensus among health professionals is once a week. But not just any time or day once a week. Here’s what you need to know.

The Timing is Key

Standing on ScaleYour bodyweight fluctuates throughout the day and from day to day, so choosing a certain time and day to weigh yourself every week is critical. This gives you the most accurate depiction of how much you fluctuate from week to week.

So, for example, start every Monday morning with stepping on the scale. If you tend to overeat on the weekends and get back on track during the week, choose Wednesday morning instead. You want an accurate reading that will allow you to determine whether you need to make changes to your diet or workouts, so this is a personal choice.

Regardless of when you weigh yourself, don’t let it ruin your day. If the number is higher than you’d like, take it as constructive criticism to rethink your workout and diet plans. This is a great way to keep you on track and hold you accountable, not tear down your motivation.