Fitbit is dedicated to developing the most accurate fitness devices on the market.
If you wear a wrist-based Fitbit device and move your body while keeping your arms still (or vice versa), you may see a slightly different step count than if you wear a device clipped to your clothing.
If you wear your device in a loose-fitting accessory such as a bangle or pendant, you may see a slightly different step count than if you wear a classic band. During workouts and sleep, we recommend wearing the classic band. Make sure the band fits securely but isn't too tight.
For more information, see How do I wear my Fitbit device? and How do I track heart rate with my Fitbit device?
If you're doing something like pushing a stroller or shopping cart, your wrist-based device will count your steps but the total may be slightly lower than usual.
If you're walking or running outside, use GPS to capture your route, pace, and distance. For more information, see How do I use GPS on my Fitbit device?
For wrist-based devices, it's important to specify whether you wear the device on your dominant or non-dominant wrist during setup:
- The dominant wrist setting decreases the sensitivity of step counting and should reduce any over counting of steps when your body is not moving. Your dominant hand is the one you use for writing and eating.
- The non-dominant wrist setting increases the sensitivity of step counting and should reduce any under counting of steps.
To start, the Wrist setting is set to non-dominant. Change your wrist setting in the Fitbit app.
If you feel that your step count and distance are inaccurate, confirm the following are correct in the Fitbit app:
- Your wrist settings (For more information, see Does the wrist I wear my device on affect accuracy?)
- Your height (For more information, see How do I manage my Fitbit profile?)
Since we use height to estimate your walking and running stride lengths, you may want to measure and manually adjust these values if your legs are longer or shorter than average. For more information, see How does my Fitbit device calculate my daily activity?
Sometimes, when you start walking, your steps may not update on your device right away. After about 10-15 continuous steps, you'll notice the steps catch up and start updating in real time with each step you take.
When you wear a Fitbit device in a clip, make sure you wear it properly. Confirm your tracker is set to WORN on Wrist 
All devices with GPS sensors require a direct path to GPS satellites to calculate location. A weak GPS signal might affect the accuracy of your route and other activity data. Your device uses your step count to calculate distance until it finds a signal, so the total distance calculated for a workout may be slightly less accurate when GPS isn't available for the entire time.
To learn more, see GPS.gov.
To improve the accuracy of your scale's readings:
- Use while barefoot.
- Make sure your feet are dry before weighing yourself.
- Place the scale on a hard, flat surface during use.
- Balance your weight evenly between both feet when you stand on the scale.
- Weigh yourself at the same time each day to see consistent trends. Your weight naturally varies over the course of the day.
- Fitbit scales needs to recalibrate if you move it between measurements or store it sideways when not in use. Up to 2 weigh-ins might be required before your scale displays accurate measurements.
- For Fitbit Aria and Fitbit Aria 2, if you turn lean mode on or off, your body fat percentage reading can be affected. For more information, see How do I use my Fitbit scale?
- For the most accurate data, your height and sex must be correct in your Fitbit profile. To update your profile, see How do I change the units of measurement in my Fitbit account?
Fitbit Aria and Fitbit Aria 2 estimate your body fat percentage using body impedance. Because several different methods can determine body fat percentage and none are 100% accurate, the scale's body fat reading may not perfectly match other scales or manual methods, such as calipers.