Why Does My Garmin Show Different Pace Than Strava? (UK 2026 Explainer)

You finish a run. You look down at your Garmin. It tells you that you held a steady 5:20 per kilometre. You feel proud. Then the file syncs to Strava, and Strava tells you the same run was 5:35 per kilometre. Same legs, same lungs, same road, two different numbers.

This happens to thousands of UK runners every weekend, and the most common reaction is to assume one of the devices is broken. Neither is. Garmin and Strava are doing two different jobs with the same raw data, and they make different choices about how to count distance, how to handle pauses, and how to smooth GPS noise. Both choices are reasonable. They just produce different numbers.

This guide explains what causes the gap, which number is more useful in which situation, and how to make the two agree more closely if you want them to. It applies to Garmin, Apple Watch, Coros, Polar and Suunto. The physics are the same for all of them.

If you train with a coaching app like Edge, this matters because you want one consistent number to train against. We will come back to that at the end.

The 5 reasons Garmin and Strava disagree

There is no single cause. The gap between the two numbers is the sum of five different choices made by the two platforms. Some matter on every run. Some only matter in certain conditions. Here is what is going on, in order of how often it shows up.

1. GPS smoothing (Strava 10-30 sec averages; Garmin reports raw)

This is the biggest one and the one most runners never hear about. Your Garmin records a GPS point roughly once a second. That stream of points is noisy. Two GPS fixes one second apart will rarely be exactly 1.6 metres apart even if you are running at a perfect 6:00/km. They jitter slightly, because GPS itself jitters slightly.

Garmin reports your pace using the raw second-by-second data. If you look down at your watch mid-run, the number you see is calculated from a short rolling window, often the last 5 seconds, sometimes 10. This makes the number on your watch feel responsive but also a little jumpy.

Strava does something different. When your file uploads, Strava re-smooths the GPS track and recalculates pace using a longer averaging window, typically 10 to 30 seconds depending on the source file. The longer window cancels out the jitter, which is good for charts, but it also slightly lengthens the recorded distance in places where you were turning corners or moving in a non-straight line. Lengthened distance with the same time equals slower pace. That is one of the main reasons Strava tends to report a slower average pace than your watch did.

2. Auto-pause logic (Strava auto-pauses below 1.5 km/h; Garmin different threshold)

Both platforms try to be helpful by pausing your timer when you stop at a junction, wait for traffic, or tie a shoelace. They just do it differently.

Strava's auto-pause kicks in when your speed drops below roughly 1.5 km/h, which is barely walking pace. Garmin's auto-pause threshold is configurable on most watches, and it triggers based on your forward speed dropping below a value you have set. The two thresholds are rarely identical. On a city run with lots of traffic lights, your Garmin might count 32 minutes of moving time while Strava counts 30 minutes 40 seconds. Same run, different totals, different average pace.

If you stopped for a long chat with a friend in the middle of a run, Strava might exclude that whole segment from moving time while Garmin recorded it as a long, very slow interval. Both numbers are defensible, they just answer slightly different questions.

3. Distance methods (Strava GPS-only; Garmin can use cadence + stride)

Strava calculates distance almost entirely from GPS coordinates. Garmin can do the same, but on most modern watches it can also blend in data from the accelerometer, the cadence sensor and, on some models, a foot pod or wrist-based stride model.

This matters most on twisty trails, in tunnels, on treadmills, and under heavy tree cover where the GPS signal degrades. Your Garmin can keep the distance estimate sensible by saying "the wearer's cadence is 178 spm, their stride length is about 1.1 metres, so they have moved roughly this far." Strava cannot do this from a plain GPS-only file. If your Garmin shows you ran 10.04km and Strava shows 9.92km, the watch is likely correcting a few weak GPS sections that Strava is taking at face value.

4. FIT file vs TCX upload differences

Garmin uploads to Strava as a FIT file by default. FIT is the dense, high-resolution format that Garmin uses internally. Apple Watch and some third-party apps upload as TCX or GPX, which are slightly older formats with less granular data.

Strava handles each format differently. A FIT file preserves the watch's own distance calculation, which Strava sometimes uses as the trusted source rather than recalculating from GPS. A TCX or GPX file forces Strava to recalculate. If you have two runs back to back, one uploaded as FIT from Garmin Connect and one uploaded as GPX from another app, you will often see different rounding behaviour even if the run itself was identical.

5. Lap auto-detection timing

If you use auto-lap (every 1km, for example) on your watch, the lap boundaries on your watch and on Strava can sit a few metres apart. Your Garmin marks the 1km lap based on its own distance counter. Strava marks the 1km lap based on its own re-smoothed distance.

The result is that a single fast 1km on your watch can appear as a slightly slower 1km on Strava, because Strava's version of "1km" started a few seconds earlier or later than your watch's version. This is also why split times often do not match exactly.

Which one should you trust?

The honest answer is that neither is the truth. They are two different reasonable summaries of what your body did. The number on your wrist is what you train to in real time, because it is the number you can react to mid-run. The number on Strava is what you see in your weekly summary, and it is the one you compare to other people's runs.

For training purposes, pick one and stick to it. If you are following a plan that prescribes "5km at 5:30/km," and your watch is the device giving you live feedback during the run, then your watch's pace is the one that matters. Worrying about the 8 seconds per km that Strava adds afterwards is a distraction from the work.

For comparing runs to each other over weeks and months, Strava is fine because it is consistent with itself. The way Strava smooths a run today is the same way it will smooth a run next month. So Strava's trends are reliable even if Strava's numbers do not exactly match your watch.

How to make Garmin and Strava agree more closely

You cannot make them produce identical numbers. The two platforms are doing different maths. But you can narrow the gap from 15 seconds per km to closer to 3 or 4 seconds per km if you want. Here is how.

1. Turn auto-pause off on both

The single biggest source of disagreement is auto-pause. If you switch it off on both your Garmin and in Strava's settings, you remove most of the moving-time discrepancy. Your overall pace will be slightly slower because stops are now included, but the two platforms will agree on what they are measuring.

2. Match manual pause behaviour

If you do pause for a real break (a coffee stop, a phone call), press pause manually on your watch and unpause when you start running again. Both platforms will see the pause as intentional and handle it the same way.

3. Set 1-second recording on Garmin

Most Garmins default to "smart recording," which saves battery by recording fewer GPS points. Switching to "every second" recording gives Strava a denser, cleaner file to work with and reduces the amount of smoothing it has to apply. Pace and distance numbers move closer together.

4. Upload directly, do not chain Connect to Strava

If you let Garmin Connect upload to Strava automatically, the FIT file goes through one extra processing step. If you instead pair your Garmin to Strava directly, or upload the FIT file by hand, you skip that step. The numbers tend to align better.

The pace you can talk at is the only one that matters. The number on the screen is just a record of what happened.

Does this affect Apple Watch, Coros, Polar too?

Yes, and for the same reasons. Apple Watch uploads to Strava through Apple Health and the conversion to Strava's format introduces the same smoothing and recalculation. Coros, Polar and Suunto all use slightly different recording windows and slightly different distance algorithms. The gap between watch and Strava exists for all of them. It is not a Garmin quirk.

The gap is usually smaller for Apple Watch because Apple Watch uses simpler GPS processing that is closer to what Strava does on its own. It is usually larger for premium Garmin watches because Garmin's distance algorithm is more sophisticated, and Strava cannot fully replicate it from the file alone.

When neither number is right (urban, tree cover, tunnels)

GPS does not work well in three situations. Tall buildings reflect the signal and the watch sees ghost positions that make you appear to zig-zag. Heavy tree cover blocks the signal entirely for short windows, and the watch interpolates a straight line that is shorter than the path you actually ran. Tunnels cut the signal completely and the watch either pauses or assumes you kept the same speed.

In any of these conditions, both your watch and Strava are working with broken data. If you are doing a tempo session through Central London, expect both numbers to be off by 5 to 15 percent. Multi-band GPS on modern Garmin Fenix, Forerunner 965, Apple Watch Ultra and Coros Vertix watches reduces the problem but does not eliminate it.

This is why heart rate is sometimes a more honest measure of effort than pace on city runs. Your heart rate does not care whether GPS is lying.

Why Edge uses your watch's pace, not a third estimate

Edge takes a deliberate decision on this. When your watch syncs to Edge, we use the pace and distance your watch recorded as the source of truth, rather than calculating our own third estimate from the raw data. The reason is simple: you trained to the number on your watch during the run. That is the number you reacted to, the number that drove your effort, the number you remember. Calculating a fourth number afterwards would just add confusion.

This means your Edge plan progresses against one consistent baseline. If your watch says you ran 5:30/km on the easy run, Edge logs 5:30/km. The next session prescribes paces based on that real number. No gap to reconcile. Free 7-day trial, then £19.99/month or £119.99/year. Try Edge free.

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