Daily weight fluctuation is normal. The average adult’s weight fluctuates up to 5 or 6 pounds per day. It all comes down to what and when you eat, drink, exercise, and even sleep.

Read on to learn more about how these factors affect the scale and when to weigh yourself for the most accurate results.

Your weight is determined by the number of calories you consume compared to the number of calories you burn.

Eating a healthy, balanced diet on par with the number of calories your body uses daily may reduce your chances of significant weight fluctuation over time.

But it can be a challenge to eat and drink in moderation every day. If your diet has been slipping, you may notice more weight fluctuation.

Some research suggests that your weight is highest on Sunday night — after a weekend of eating out or drinking alcohol — and lowest on Friday morning.

If you have a traditional Saturday and Sunday weekend, you may be able to get the most accurate measurement of your weekly weight by weighing yourself on Wednesdays.

Food high in salt and carbohydrates may cause your body to retain water. Your weight may spike until the bloat subsides.

You may be able to minimize water retention by cutting back on sugary drinks and processed foods.

Adding potassium– and magnesium-rich foods to your diet may also help balance out your sodium levels.

No matter the caloric content, foods and beverages all weigh something. Drinking an 8-ounce glass of water will add weight to your body because it has weight. The same is true for the vegetables in your salad.

However, healthy foods and water pass through your body quickly, so eating a balanced diet can mean less fluctuation. Foods high in carbohydrates, sodium, and fat take longer to process and expel through waste.

Your body uses foods and fluids for hydration and energy. After it’s successfully gleaned the nourishment it needs from these sources, it will begin to expel the leftovers as mucus, sweat, urine, and stool. This can cause a slight decrease in weight.

Diet plays a major part in daily weight fluctuation, but other factors can also contribute to the scale moving up and down.


Expending energy by burning calories can result in weight loss. But if you’re adequately hydrating, you may not see immediate weight loss on the scale. That’s because the water you drink replaces the water you’ve lost via sweat.

Water, however, contains no calories and won’t cause weight gain over time.

Exercise burns calories, so if you burn more calories than you eat and drink, you will lose weight.

One caveat: If you’ve recently started or switched up your routine, you may notice slight weight gain as you begin to build muscle mass.


Some medications cause your body to retain water, increase your appetite, or change your metabolism.

This includes:

  • insulin
  • thiazolidinediones
  • beta-adrenergic blockers
  • tricyclic antidepressants
  • selective serotonin reuptake inhibitors
  • lithium

If you think your medication is affecting your weight, make an appointment with the prescribing doctor.

They can help you determine the reason for fluctuation and discuss your options moving forward. This may mean switching medications or making dietary and fitness changes.

Menstrual cycle

Your menstrual cycle can cause your body to retain more water during certain times of the month, resulting in a slight weight gain. You may notice that your base weight is a bit higher than normal on the first day of your period. Your daily weight should go back to average within a few days of your cycle beginning.

Alcohol intake

Alcohol isn’t processed the same way as other beverages and foods, so it can take longer for your body to eliminate. It also slows the digestion of other substances, which can lead to water retention.

Beyond that, alcohol contains extra calories that you may not be accounting for in your overall diet. You may also pay less attention to your overall calorie intake while drinking alcoholic beverages.


Your weight may go up or down due to a bout of illness, like the flu, or as a result of a chronic condition.

While conditions like underactive thyroid, Cushing syndrome, and polycystic ovary syndrome can lead to unexpected weight gain, diabetes and Crohn’s disease are often associated with unexpected weight loss.

If you’re experiencing other unusual symptoms — or have a diagnosed underlying condition — see a doctor. They can determine whether your symptoms are related to an underlying condition and advise you on next steps.

Be consistent when you weigh yourself. Your lowest weight of the day will be after you wake up and empty your bladder. You may choose to weigh yourself at another time of day, but you must continue to weigh yourself at that time on the same scale for an accurate measurement.

If you want to assess your average weight fluctuation

Weighing yourself throughout the day won’t measure overall pounds gained or pounds lost, but it will help you assess your overall amount of weight fluctuation during the day. You may want to weigh yourself in the morning, in the middle of the day, and at night to get a sense of your weight fluctuation.

If you want to lose 2 to 3 pounds

You can measure weight loss by weighing yourself at the same time of day — under the same circumstances, such as with shoes off — to determine if you’ve lost any real weight.

You will lose weight by expending more calories than you consume. Losing a small amount of weight will likely require just a bit more restraint than usual. Cutting out extra snacks or reducing your portion size may help you lose a few pounds within the next week or two.

If you want to lose more than 3 pounds

You can use your daily base weight to help measure any amount of weight loss. One 2013 study suggests that daily weigh-ins can contribute to significant weight loss. The study also factored in exercise and diet.

Make sure you keep in mind that you need to burn more energy, consume less energy (calories), or do a combination of both to lose weight. Generally speaking, losing 1 to 2 pounds a week is considered a healthy approach.

Determining your base weight by keeping things consistent is key. Here are a few tips for measuring your daily weight:

Use a scale as your primary method

Weigh yourself with a scale that you know is accurate, and use the same scale every day. Make sure the scale is on a flat, hard surface to avoid inaccurate readings.

Weigh yourself at the same time every day

Try to weigh yourself at the same time every day. It’s often recommended that you weigh yourself first thing in the morning after you use the bathroom.

Try with or without clothes

Try to weigh yourself without clothes or with just undergarments. The weight of your clothing can vary, affecting the number on the scale.

Incorporate other measurements

There are more ways than the scale to measure your body composition and overall weight. The ways your clothes fit on you may help you assess weight fluctuation. Measuring the size of your waist, arms, and other areas can also show you how your body is changing.

However, body size isn’t the only way to assess your overall health. For example, you can measure your fitness level by tracking your heart rate while at rest and when engaging in aerobic activity. Counting your repetitions can help assess your strength, and testing your limits in certain stretches can help measure your flexibility.

Daily and even weekly weight fluctuations are normal and usually aren’t cause for concern. But if your weight fluctuates more than 6 pounds in either direction within a six-month time frame, see a doctor or other healthcare professional. This could be a side effect of a medication you’re taking or a sign of an underlying health condition.