PackCal is a data field, not a separate activity you start. After installing it from the Connect IQ Store:
Give PackCal a whole single-field screen and it shows the calorie hero plus a live HR / pace / ascent rail, a pack-bonus pill, and a timer-and-distance footer. In a denser multi-field layout it shows a compact labelled number.
No. PackCal is a one-time $1.99 USD purchase via Garmin Pay, with no trial. A data field has no buttons or input surface of its own, so the usual code-based trial flow doesn't fit it. Instead, this site is meant to do the trial's job, the screenshots, the calorie-math page, and this FAQ show exactly what you get before you buy.
If you want a fuller, try-before-you-buy rucking experience, its companion app RuckTrack offers a 7-day trial on its KiezelPay listing.
While you move, PackCal's load-aware total is the hero of its cell on the watch. After you save, the pack-aware fields land in Garmin Connect under the activity's Stats → Connect IQ section: pack weight, pack calories, and terrain.
The big headline calorie at the top of the activity is Garmin's own heart-rate-based estimate, and it doesn't know about your load, Garmin doesn't let a third-party data field overwrite that field. Both numbers are correct for what they measure: the headline answers "how hard did your body work?" and PackCal answers "how much of that came from the pack?" The Calorie Math page explains the gap.
PackCal shows a load-aware number where the math is honest:
Elliptical and stair machines are left out on purpose, and it is worth saying why. On those the calorie estimate comes from your heart rate, and wearing a vest already raises your heart rate, so scaling that number by pack weight would count the load twice. There is no honest low-intensity window to correct for, the way there is on a treadmill walk. An earlier version of this page listed both as supported, which was wrong.
PackCal uses the Pandolf equation, a published military physiology model that estimates metabolic cost from body weight, pack weight, walking speed, grade, and terrain (Road, Gravel, Trail, Sand, Snow). When you slow below walking pace or GPS isn't usable, PackCal falls back to your watch's native heart-rate-based estimate so calories don't stall. The total shown is a hybrid of both. Full details on the Calorie Math page.
Yes, on a treadmill or an indoor walk. PackCal uses an Auto path there: it takes your watch's heart-rate calorie estimate and scales it up by the pack weight you've set. No GPS required, and the subtitle shows the resulting "+N%" so you can see what the load added. Elliptical and stair machines are deliberately not included.
PackCal has its own settings right on the watch, no phone needed, reachable from the activity's Connect IQ Fields menu for PackCal. You can set pack weight, weight unit (lb or kg), terrain, an optional body-weight override, and energy unit (kcal or kJ).
If you change your pack weight mid-activity, PackCal picks it up within about a second. The change applies forward; past calories aren't recomputed.
Two reasons:
If you've never set a pack weight, or your body weight is unknown (no profile weight and no override), it shows SETUP NEEDED instead.
Yes. PackCal has an Energy Unit setting (kcal or kJ) in its on-watch settings; it's display-only. The FIT file always records kcal, matching how Garmin stores energy.
PackCal runs on the Forerunner (70 / 165 / 170 / 255 / 265 / 570 / 955 / 965 / 970), fēnix 6 Pro / 7 / 8 / E, Enduro 2 and 3, epix and epix Pro, Venu (2 / 3 / 4 / X1 / Sq 2), vívoactive 5 and 6, Instinct 3 and Instinct E, plus the Approach, D2, Descent, MARQ, tactix and quatix families. See the devices page for the full per-family list, or check the Connect IQ Store listing for the live compatibility check.
Why some older watches are not supported. PackCal is a paid app, and Garmin only sells paid Connect IQ apps on a specific list of products. Watches such as the Instinct 2, the first-generation Enduro, the Venu Sq, the vívoactive 3 and 4, and the Forerunner 55/245/645/745/945 cannot install PackCal even though the app is built for that hardware. The restriction is Garmin's and applies to every paid Connect IQ app, not just this one. Garmin publishes the current list on its App Sales page.
On the most memory-limited watches that can install it (the fēnix 6 family, Instinct E and Instinct 3 Solar), a full single-field screen shows the simpler labelled number rather than the calorie hero with the live rail and pack-bonus pill around it. The calorie math is identical on every watch.
No. Its settings stay on your watch. Meridian operates no servers, runs no analytics, has no companion phone app, and uses no third-party SDKs. Full details on the Privacy page.
Yes, that's the whole point of a data field. PackCal rides inside the activity you already use, so its load-aware calories run together with Garmin's native maps and turn-by-turn navigation, and alongside other Connect IQ data fields such as Stryd's power field (up to your watch's data-field limit). Add PackCal to a native walk-type activity (Ruck, Walk, or Hike), drop in any other fields you want, and they all record to the same activity.
If you'd rather have a dedicated rucking app with its own purpose-built screens instead of adding a field to a native activity, see RuckTrack.
They share the same calorie engine and write consistent FIT fields, but they're different shapes:
Get PackCal if you just want load-aware calories added to your existing setup; get RuckTrack if you want the complete rucking experience.
Garmin permits returns of paid Connect IQ apps (commonly reported as a 48-hour window). The mechanism is typically to uninstall the app from your watch shortly after purchase; Garmin then reverses the charge automatically. If you have trouble, contact Garmin Support. Meridian doesn't process payments and has no access to your purchase.
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