Garmin Forerunner 170 review

I haven't worn the Forerunner 170. This review works from three published tests by the5krunner, DC Rainmaker and The Run Testers, plus the specifications page in Garmin's manual. Every measured number below belongs to the outlet named beside it. The 7.8 is my opinion of what they found.

The Forerunner 170 costs Not verified yetNot verifiedNot verified, checked . The Forerunner 70 is Not verified. For most runners, that gap is the whole decision.

What the extra money buys over the Forerunner 70

Hardware, mostly. The 170 adds a barometer, a compass and a gyroscope. It also adds Garmin Pay, open-water swim tracking and pairing with cycling power meters and smart trainers.

It doesn't add better tracking. DC Rainmaker wore the two side by side in May 2026 and reported identical GPS and heart rate results from both. If you run on roads and carry your phone anyway, the 70 records the same run for less.

And the dearer watch lasts shorter. Garmin's smartwatch claim, as DC Rainmaker tabulated it, is up to 10 days for the 170 against up to 13 for the 70. You pay more and charge more often. That annoys me.

Battery: Garmin's claims and what testers got

Garmin claims up to 20 hours with GPS only and 14 hours with all satellite systems, per the5krunner. In two continuous recording tests, the5krunner got 20.83 hours and 16.67 hours, an average of 18.75.

There's a catch. the5krunner couldn't tell which satellite mode the watch had used. So I can't say which claim those runs were measured against. The first run beat both figures. The second beat 14 hours and fell short of 20. Either one covers a marathon with hours to spare.

Daily use is a different story. The Run Testers had three testers running every day with the always-on display switched on, and they charged about every 3.5 days. That's a long way from 10.

Accuracy

the5krunner's parkrun measured 5.00 km, 7 m under the average of three other devices. A 62.97 km ride came out 57 m over the others' average. Through an urban canyon the 170 logged 2.98 km against 2.94 km from a Stryd footpod. the5krunner found no consistent bias in either direction.

Heart rate was checked against a Forerunner 970 paired with an HRM 600 chest strap. On the parkrun, the bias was -0.1 bpm, with limits of -2.6 to +2.5 bpm. That's close.

Short intervals were looser. The bias was +0.5 bpm, but the limits widened to -7.8 to +8.7 bpm. If you train interval sessions by heart rate zone, I'd budget for a chest strap.

the5krunner scored the watch 86%.

One caveat. the5krunner lost some 170 files and used the Forerunner 70 as a stand-in for tests 4 to 6; only tests 1, 2, 3 and 7 are 170 data. Since DC Rainmaker saw identical output from the two watches, I don't think it changes the picture. You should still know it.

Swimming and the cold

Garmin rates the 170 at 5 ATM and IPX8, equal to the pressure at 50 m. The manual lists an operating range of -20°C to 60°C (-4°F to 140°F). Open-water swim tracking is one of the things the 70 lacks, and for triathletes it's the best reason to pay up.

When I'd buy something else

Forerunner 170 Music: same watch with offline music. If you run without your phone, that's the one.

Forerunner 970 ($749.99Not verifiedNot verified). It's Garmin's top Forerunner, with multiband GPS, and it was the5krunner's heart rate reference. The 170 was 40 m off a footpod in the5krunner's urban canyon test, so I'd find the step up hard to justify for road running. The Forerunner 570 sits between the two.

Coros Pace 4 ($249Not verifiedNot verified). It's the closest-priced running watch I track, and The Run Testers put it next to the 170. Check both prices on the day before you choose.

Who I'd buy it for

Swimmers who train in open water. Cyclists with a power meter or a smart trainer. Anyone who wants to leave the wallet at home on a long run and pay with Garmin Pay.

Everyone else gets identical runs from the Forerunner 70 and three more days between charges, by Garmin's own claims.