You hand over 10 materials of one grade and get 1 of the grade above. It works the same from Uncommon to Rare as it does from Epic to Legendary, which means a single Legendary material is worth 1,000 Uncommon ones.

Combining is not free, every attempt burns Glittering Powder, Darksteel and Copper. A Rare costs 2 powder, 1,000 Darksteel and 2,000 Copper. An Epic costs 25 powder, 5,000 Darksteel and 20,000 Copper. A Legendary costs 125 powder, 25,000 Darksteel and 100,000 Copper. The fee is charged for every single material you produce, so the real bill grows fast as you climb.

The recipe is identical for every Dragon material: 300 Steel, 100 Dark Heart Stone and 100 Moon Shadow Stone, all three at Legendary. Switching category changes the names of those three materials, not the recipe.

Building the chain from the bottom gets heavy: 300,000 Uncommon Steel, 100,000 Uncommon Dark Heart Stone and 100,000 Uncommon Moon Shadow Stone, plus 287,500 powder, 87,500,000 Darksteel and 250,000,000 Copper in combine fees. Start from Rare materials instead and the same job drops to 187,500 powder, 37,500,000 Darksteel and 150,000,000 Copper.

Scale and Claw share the same trio: Steel, Dark Heart Stone and Moon Shadow Stone. Leather uses Steel, Quintessence and Exorcism Bauble. Horn and Eye ask for Platinum, Illuminating Fragment and Anima Stone.

The game spends tradable materials during a craft exactly like normal ones, it makes no distinction between them. That is why the calculator adds up whatever you type into the two boxes and treats it as one number.

You decide how far down the plan goes. Anything below the grade you pick is left out of the maths, and whatever is missing at that grade is what you have to farm. Already sitting on Epic materials? Start at Epic. Want to see the full bill? Go all the way down to Uncommon.

Mythic is not a material grade, so it has no place in this calculation. Materials stop at Legendary. Mythic gear comes from awakening a Tier 4 Legendary item pushed to Stage 15 with a Divine Dragon's Soul, and you invoke that Soul with 3 Legendary Dragon materials, guaranteed on the sixth try if the first five fail.

The total you see only counts combine fees. The fee charged on the last step, when the Dragon material itself is crafted, is not in there yet, so the in game number can come out slightly higher.