How to Do Quick Math in the REI Search Bar

Typing a Calculation

Open your inventory so the REI search bar is visible, then click into the search field and type a math expression instead of an item name. The mod evaluates it live and shows the result in place of item search results. Basic operators work as you'd expect: +, -, *, and /. For example, typing 64*3 gives you the product without you ever leaving the inventory screen.

Reading the Result

Because the search bar is normally used for filtering items, the calculator result appears as the search output. If you want to go back to searching for items, just clear the field and type a normal item name again. There is nothing to toggle — the mod decides based on whether your input parses as a valid expression.

When to Use It

This is meant for fast, everyday arithmetic while playing: figuring out how many of a resource you still need, splitting a total across chests, or checking a total cost before trading. It is not a graphing or scientific calculator, so keep expressions to the four basic operators. If you need the same calculation outside the inventory, the /calc command accepts the same expressions.