You can measure distance while walking using your smartphone’s GPS, a pedometer that counts your steps, a calibrated stride length, or simple landmarks like city blocks. Each method has trade-offs in accuracy and convenience, and the best choice depends on whether you’re walking outdoors or inside, on a trail or through a city. Here’s how each approach works and how to get the most accurate results from it.
Use Your Phone’s GPS for Outdoor Walks
The simplest method for most people is a GPS-based app on your smartphone. Apps like MapMyWalk, Strava, and Apple Health use your phone’s built-in GPS receiver to plot your position every second and calculate the distance between those points. This works well on longer outdoor walks, especially in open areas where the phone has a clear view of the sky.
GPS does have blind spots. In open conditions, a phone’s GPS is accurate to roughly 3 to 5 meters horizontally. On typical city streets lined with five-to-seven-story buildings, that error can jump to around 12 meters. In dense downtown corridors surrounded by skyscrapers, horizontal errors can reach 13 meters or more. Each of those small position errors gets baked into your distance total, so a walk through a canyon of tall buildings may read longer than it actually was.
GPS also struggles to detect short walking bouts. One study found that GPS-based tracking captured walks under 100 meters only about 9% of the time, while an accelerometer-based tracker detected those same short walks 47% of the time. If your walk involves lots of stopping, turning, and short segments, like walking through a mall parking lot or running errands, GPS will likely undercount your total distance. For sustained walks of 500 meters or more, GPS performs much better.
Count Steps and Convert to Distance
Step counting is the other main way phones and wearables estimate distance. Instead of tracking your position via satellite, an accelerometer inside the device detects the rhythmic motion of your body with each step. The device multiplies your step count by an estimated step length to produce a distance figure. This works both indoors and outdoors, which is its biggest advantage over GPS.
The accuracy depends heavily on two things: getting an accurate step count and using the right step length. Where you wear the device matters more than most people realize. Hip-worn pedometers tend to be more accurate during actual walking, while wrist-worn trackers undercount steps during steady walking by about 6%. The flip side is that wrist devices overcount steps during everyday activities like cooking, gesturing, or folding laundry by roughly 22%, because arm movements get misread as steps. Over a full day, wrist-worn devices report about 11% more total steps than hip-worn pedometers.
If you’re using step counting primarily to measure walking distance, carrying your phone in a pocket near your hip or clipping a pedometer to your waistband will give you the most reliable count.
Calibrate Your Personal Step Length
The default step length programmed into most apps and pedometers is a rough average. To get a more accurate distance reading, you can measure your own step length in about five minutes.
- Find a flat surface like a sidewalk, hallway, or parking lot where you can walk in a straight line.
- Mark a starting point on the ground with tape or chalk.
- Walk 10 steps at your normal pace and mark where your foot lands on the tenth step.
- Measure the total distance between the two marks with a tape measure.
- Divide by 10 to get your average step length.
Repeat the process at a brisk pace, since your step length changes with speed. Most apps let you enter a custom step length in their settings. If yours doesn’t, you can still use the number to do your own math: multiply your step count by your step length to get distance.
Your height is the biggest predictor of step length. Research on adults found that people 5’3″ (160 cm) and under have an average stride length of about 1.24 meters (roughly 4 feet), while people 5’7″ to 5’11” (161 to 170 cm) average about 1.30 meters, and those 5’11” and taller average around 1.33 meters. A stride is two steps, so divide those numbers in half to get a single step length. Men tend to have slightly longer strides than women even at the same height, with male stride lengths averaging 1.31 to 1.32 meters compared to 1.24 to 1.27 meters for women.
Estimate Distance Using Pace and Time
If you don’t have a phone or pedometer, you can estimate distance with just a watch. Walking speed is surprisingly consistent for a given effort level, so once you know your pace category, a simple multiplication gives you a reasonable distance figure.
A large meta-analysis of outdoor walking speeds in healthy adults found these averages:
- Slow, easy pace: about 49 meters per minute, or roughly 1.8 miles per hour
- Normal, comfortable pace: about 79 meters per minute, or roughly 3 miles per hour
- Brisk, purposeful pace: about 103 meters per minute, or roughly 3.8 miles per hour
At a normal comfortable pace, you cover about a mile every 20 minutes or a kilometer every 12 to 13 minutes. At a brisk pace, a mile takes closer to 16 minutes. These are averages for flat ground. Hills, rough terrain, and heavy foot traffic will slow you down.
Use Landmarks to Gauge Distance
City blocks offer a surprisingly useful built-in measuring system. Block sizes vary by city, but common patterns are consistent enough to be helpful. In Chicago and many other American cities built on a grid, a standard block is about 330 feet (100 meters) on its short side, meaning 16 short blocks equal one mile. In Manhattan, the short blocks running east-west are about 264 feet (80 meters), while the long blocks running north-south are about 900 feet (274 meters), so roughly 20 short blocks or 6 long blocks make a mile.
If you walk near a school or university, a standard outdoor running track is exactly 400 meters (about a quarter mile) for one lap in the innermost lane. Four laps equals one mile. Walking on a track is also one of the easiest ways to verify whether your phone or pedometer is giving you accurate readings.
Measuring Distance on a Treadmill
Treadmills display distance directly based on belt speed and elapsed time, which makes them one of the more straightforward ways to know exactly how far you’ve walked. The reading is generally accurate because the machine controls the speed mechanically rather than estimating it from body motion.
If you want your fitness app to also reflect treadmill distance, look for an app that supports indoor or treadmill mode. In this mode, the app relies on your phone’s accelerometer rather than GPS, using your step count and stored step length to estimate distance. The accuracy of this estimate depends on whether you’ve calibrated your step length, since treadmill walking often produces a slightly shorter step than outdoor walking at the same speed. Walking a known distance on the treadmill and comparing it to your app’s reading is a quick way to check.
Combining Methods for Better Accuracy
No single method is perfect in every situation. GPS excels on long, uninterrupted outdoor walks but fails indoors and struggles in cities. Step counting works everywhere but drifts if your step length estimate is off. Time-based estimation is the least precise but requires no equipment at all.
The most practical approach is to use GPS for outdoor walks and step counting for everything else, with a calibrated step length entered into your device. If you notice your app consistently over- or underestimates a route you know the distance of, adjust your step length setting by a few centimeters until the readings match. Over time, this hybrid approach will give you distance figures that are accurate to within 5 to 10% of the real number, which is precise enough for tracking fitness, planning routes, or hitting daily distance goals.