Do you need a running watch?

Start with what a phone already does

A modern phone has a GNSS receiver, an accelerometer and an app ecosystem. It will record a route, calculate pace and distance, and sync to Strava without you buying anything. For a large number of runners that is genuinely the whole job, and the honest answer to this question is no.

We should say plainly what we cannot tell you: there is no study in our source library that measured phone GPS distance accuracy against a watch under the same conditions. Anyone telling you a watch is X% more accurate than a phone is making it up. What exists is a 2020 validation of eight sport watches against a trundle wheel accurate to one centimeter, which found 3.2% to 6.1% distance error overall and 0.9% to 4.1% on a track, with only Polar's receivers under 5%. Every watch in that study was single-frequency, so it does not describe current hardware either. The device-by-device record is at GPS accuracy by device.

The three things that actually change on your wrist

1. The data is available during the run. This is the real difference, and it is not about accuracy at all. A watch shows current pace, lap pace and heart rate at a glance, which is what makes structured training possible: intervals at a target pace, a tempo run held in a heart-rate band, a long run kept deliberately slow. You cannot run a workout off a phone in your pocket.

2. It lasts longer than a phone. Manufacturer-stated figures on the three watches here run from 17 to 38 hours of GPS recording. A phone running a GPS app with the screen waking is working hard, and a long trail day is where that gap stops being theoretical.

3. It measures heart rate — badly.A watch adds a wrist optical sensor, and this is the part most buyers assume is an upgrade. It is the worst-performing sensor position in every published comparison we have found. In a 2025 peer-reviewed placement study, a wrist-worn watch recorded a bias of approximately 33 bpm during explosive work, the largest error in the paper, while a forearm sensor held a bias under 0.1 bpm on a graded treadmill protocol. Pooled across 249 validation studies, wearable heart rate sits near ±3% — but that figure flatters the wrist, because it includes straps and armbands.

The cheapest honest setup

Here is the recommendation most sites will not make, because it sells less: if you already carry a phone and your reason for buying is better data rather than convenience, a chest strap paired to your phone beats a cheap watch on measurement quality for less money. The strap measures the heart's electrical signal directly — it is the instrument research uses as its reference — and your phone is already doing the positioning. The ranked field is in most accurate heart rate monitors, and the budget end is in best budget heart rate monitors.

What that setup will not do is show you pace on your wrist mid-interval, survive a 30-hour ultra, or come swimming with you. If any of those matter, buy the watch.

If you are buying a watch, buy the right rung

You do not need the flagship, and the three watches on this page are deliberately the three rungs rather than the three best. All of them record pace, distance, heart rate and the training metrics that follow from those.

The COROS PACE 3 is the endurance-per-dollar entry: COROS states 38 hours of full GPS and 15 days of regular use in a 29-30 g watch with a dual-frequency GPS option. The caveat is published and real — the only independent test of PACE 3 wrist heart rate found it diverging during and after rapid intensity changes, which is exactly when interval training needs it.

The Garmin Forerunner 265 is the step up that buys the thing a cheap watch cannot fix: an all-systems multi-band receiver, published at up to 14 hours. It is also the only watch here with a peer-reviewed measurement behind any of its derived numbers — in a 2025 study of 100 runners its threshold test returned a usable result 65.2% of the time, the best completion rate of the three watches tested, using a chest strap rather than the wrist sensor.

The Garmin Forerunner 165is the cheapest AMOLED route into Garmin's platform: 11 stated smartwatch days, 19 hours GPS-Only, 17 hours All Systems. Garmin publishes no multi-band row for it, because it has no multi-band mode — the full comparison is at Forerunner 165 vs 265.

Four reasons not to buy one

• You run to get away from screens. A device that buzzes at every kilometer is a worse run for some people, and no amount of data fixes that.
• You only look at the summary.If you never check pace mid-run, the watch's main advantage is one you are not using.
• Your complaint is heart rate. A new watch will not fix it — the wrist is the problem, not the brand. The measured fix is in better heart rate accuracy.
• You want it for sleep and recovery. Different purchase entirely; the published evidence there favors a different form factor, which we work through in smart ring vs watch for sleep tracking.

If the answer is yes and the budget is the constraint, the ranked list is best running watches on a budget; if it is yes and you are choosing for the long term, start at best running watches.

The decision in three questions

• Do you run workouts with targets?Intervals, tempo efforts or zone-controlled easy runs need the numbers in front of you. That is the watch's one irreplaceable job.
• How long is your longest day? Under two hours and a phone copes. Beyond that, stated GPS hours stop being a specification and start being the difference between a recorded run and a dead battery.
• Is heart rate the reason? Then buy the sensor, not the watch. Every wrist optical sensor on this site is unvalidated in its current generation, and the position itself is the weakest one measured.