Garmin Watch Size Guide: Venu 4 and Forerunner 570

Choose a Garmin watch size by how the case and band fit your wrist, how easily you can read the screen and how comfortable it feels during the activities you do. A smaller watch is not automatically a women's watch, and a larger one is not automatically the better model.

Your size choices at RBO

The case measurement is not your wrist circumference. Display size is a separate measurement. Battery estimates refer to smartwatch mode; GPS, music and display settings can reduce runtime.

Measure your wrist before choosing

Use a flexible measuring tape where the band will sit, or wrap a strip of paper around your wrist and measure its length. Compare that measurement with the band range on the exact product listing. A case diameter cannot tell you whether a particular band is long enough.

Garmin recommends a snug, comfortable fit above the wrist bone. Do not tighten a band just to make a large case stay in place. The sensor should make contact without the watch becoming uncomfortable.

Compare the case as well as the screen

Look at how far the case extends across your wrist. Bend your wrist, slide a sleeve over it and check whether the watch shifts when you move. These checks are especially useful if you plan to sleep in the watch as well as wear it for workouts.

A larger display may be easier for you to read, but try the data layout you intend to use. The question is whether you can comfortably see your pace or workout information, not simply which screen has the larger number.

Venu 4: 41 or 45 mm?

Compare the two sizes when everyday wear is a priority. Choose 41 mm if you prefer a less prominent case, or examine the 45 mm if you value its larger display. The battery ratings differ by size. Check the listing for the color offered in each version rather than assuming every color is available in both.

Forerunner 570: 42 or 47 mm?

Both sizes belong to the same 570 family. The 42 mm option has a smaller case and display; the 47 mm has the larger display and a different smartwatch battery estimate. Pick the fit you can wear comfortably through a run and the rest of your day.

Choose the watch family first if features differ

If you are comparing Venu with Forerunner rather than sizes within one family, read our Venu 4 vs Forerunner comparison. This guide handles fit; that article handles the buying decision.

Compare Garmin watches at Red Beard’s

Browse our Garmin watches or visit our Mobile store. Tell us how you plan to use the watch and which features matter most. Check availability before making a trip for a specific size or color.

Sources and product details

Venu 4 manual; Forerunner 570 manual; Venu 4 battery ratings. Specifications reviewed October 14, 2026. Manufacturer battery figures are estimates that depend on settings and use. Check the exact product page for current price and availability.