Why Are Bathroom Scales Not Accurate

Keeping track of your weight can be pretty frustrating, especially if the reading you see on the scale tends to fluctuate.  Some people wonder if their bathroom scale is really accurate, or whether their weight really just fluctuates a lot.

accurate bathroom scale dial
There are several factors that can make a scale inaccurate.

Truthfully, your weight can fluctuate as much as 3 to 5 pounds in a single day.  This has a lot to do with how much you eat, how much you use the bathroom, and how much water your body retains. If you are weighing yourself at the same time each day, you can still see some fluctuation.  

If you are keeping track of your weight for medical purposes, it is really important that you use an accurate scale to get an accurate reading.  

Is the Scale Actually Inaccurate?

Is your bathroom scale really inaccurate, or could there be something underlying that is causing you to get an inaccurate weight reading?  There are quite a few reasons that your scale may be inaccurate. Some scales are just sub par when it comes to quality, and just don’t offer the most accurate results.  This is why you should always check into the accuracy of a scale before you purchase.

Sometimes, however, even an accurate scale can give you a reading that is not correct.  This can be frustrating, but there are some tell-tale reasons why this occurs.

Reasons an Accurate Scale Could Give an Inaccurate Reading

If you have a high quality, accurate bathroom scale that gives an inaccurate reading, there could be a good reason why.  Here are some of the common causes of inaccurate weight readings.

#1 – Your Floor Could Be the Cause

bathroom scale on uneven floor
Using a bathroom scale on an uneven floor can cause it to be inaccurate.

Did you know that the type of flooring that you have under your scale can really impact the reading?  If your scale is on a soft floor, such as carpet, it can cause the reading to be off. It is always best to put your scale on a hard, solid floor, such as a tile floor.  This allows the scale to stand firmly on the ground, giving the most accurate result possible. It is also important that the floor is even. Some tile floors may be uneven, and may still give an inaccurate reading.

#2 – You May Be Weighing Yourself at the Wrong Time of Day

Most people know that weighing yourself at the same time each day gives the best results, but did you know that there is actually a certain time of day that is better for you to weigh?  Weighing first thing in the morning is always best. Do it before you eat anything that day, but be sure to use the bathroom first. This helps to ensure that you get a true weight reading, without added food or fluids in your body.

Also wear the same type of clothing (ideally just your underwear) every time. If you weigh yourself one day naked and the next day you are in your sweatpants and slippers – you’re not going to get accurate results.

fully clothed on scale on uneven floor
Two mistakes: Floor boards are uneven and fully clothed with shoes and long pants.

#3 – Professional Scales and Home Scales May Vary

Not everyone can afford to buy a professional scale for their home, as they are usually upwards of hundreds of dollars (if not more). The truth is, however, professional grade scales are not always more accurate than a home scale. If you notice a difference between the scale at your doctor’s office and your home scale, it doesn’t always mean that one of them is inaccurate.  

The best way to keep a good watch on your weight is to weigh yourself with the same scale.  Consistency is key. If you weigh more on your doctor’s scale than you do at home, it may not mean that you gained some weight on the way there.  

The amount of clothes you are wearing can also play a major role. When I go to the doctor the nurse weighs me in the hall before I go into the consult. At home I weigh myself in my underwear but I’m not really going to strip down in front of everyone at the doctors office so really not able to compare apples to apples. Apart from being different scales, I’m wearing different clothes. I also could be wearing more or less clothing since the last doctor’s appointment so I’m surprised they don’t have a procedure down to make the measurement more accurate from visit to visit to compare my weight trend over time…but oh well.

#4 – Your Batteries May Be Getting Weak

Home scales may also start to be inaccurate when the batteries are starting to go out.  Keeping good batteries in your bathroom scale is a good idea. Typically, the batteries will last a long time.  You shouldn’t have to replace them too often, but every few months or so it is a good idea to swap them out. Even if they are still working, it may be a good idea to go ahead and switch them out.  Put the other batteries into a TV remote or something that doesn’t rely on extreme accuracy.

Choosing the Right Scale for Accuracy

There are just so many scales out there, so picking the best one can really seem impossible. Do your research ahead of time, and you are sure to find an accurate scale.  Not all scales are made equally.  Here are some tips that you can use to help you choose the right scale when it comes to accuracy. If you are looking for a new accurate scale and to save time on research we’ve done the heavy lifting for you here with our reviews of the best bathroom scales for accuracy.   While professional medical scales you see at doctor’s offices are generally more accurate and reliable than digital home bathroom scales, you don’t necessarily have to spend a ton of a money for an accurate scale.

Some of the most inexpensive bathroom scales we’ve researched here can measure to .02 pound and are consistent (especially if placed on a stable, flat surface and you are weighing yourself at the same time everyday). 

#1 – Look for Precision Sensors

Most of the best scales will have at least four precision sensors that are used to measure your weight.  Check into the sensors on a bathroom scale before you buy. Sensitive sensors are best, because they can offer a more accurate reading.

#2 – Decimal Points Matter

To get the most accurate results from your scale, choose a scale that will measure to the nearest tenth.  Some scales, for example, may give a reading of 138 pounds, while a more accurate scale may measure to 138.2 pounds.  This can be beneficial when it comes to tracking weight gain or loss.

#3 – The Platform Matters, Too!

medical scale with platform
Professional and medical scales have large, wide platforms so patient can stand firmly with both feet completely on the scale.

The actual platform that you stand on when you step onto your scale can make a difference in the accuracy of your reading.  If your feet do not fit all the way on the platform, then you may not get the most accurate reading possible. Choose a scale that has a large platform that will be comfortable for you to stand on.  If you have a wide hips or large stature you may really need to consider a an extra wide platform.

The home scale we like best for this is the My Weigh Talking Bathroom Scale. It’s specifically designed for high capacity (up to 700 pounds) but really has a lot of great features for any home user including the fact that it talks to you! No more looking down at the scale to try to read the numbers. You can see our full review of the scale here. 


As you can see, the accuracy of your bathroom scale can really depend on a lot of different factors.  If you are considering getting a new bathroom scale, let this be your guide when it comes to choosing one that is going to give you an accurate reading each and every time.