Crafting Resource Calculator

About this calculator

In crafting-based games, a recipe specifies how much of each material is needed per item produced; scaling that up for a batch and subtracting what's already in inventory gives the actual shopping or gathering list. Adding a wastage or fail-rate factor — common when crafting has a chance to consume materials without producing an item, as in many MMOs — inflates that requirement to account for expected losses: materials needed = (recipe cost × batch quantity ÷ (1 − fail rate)) − current inventory.

This calculator takes a recipe's per-item material cost, the quantity you want to craft, what you already hold in inventory, and an optional wastage rate, then returns how many more materials to gather. MMO and survival-game players use it to plan farming or auction-house runs before committing to a big crafting session, and game economy designers use the same math when balancing recipe costs and drop rates during development.