I can always try now: what is grind for you? You sure can word some precise definition because you asked for it to be calibrated against some untold criteria.

• The amount of work to forge an iron set (or whatever item, upgraded or not) divided by the number of ig days it takes focusing almost only on this "task".

OR

• The amount of work to forge an iron set (or whatever item, upgraded or not) divided by the number of ig days when you happen to finally complete the whole set/item.

For in Valheim, there's a fair amount of possible activities that are less gated by equipment and stats than in some other games, thus diluting the required actions into a greater time pool. What is truly gated are interactions with biomes (not counting skimming borderlands, a risky, yet thrilling activity), and killing bosses, for example to stop some raids. Granted, this depends on the way each one likes to play, and that's where <insert your objectives and scheduled times here> becomes relevant.

For example, if you want to build a karv to explore some distant island, or reach next boss (the Elder?), then you need to process copper and tin ore. For the same amount of work (and clicking), what ig days and irl hours will this take, depending on your other activities, such as going on exploring nearby islands, farming, building the next base camp (closer to the next island), collecting other materials, surveying nice spots to build something epic?