An intuitive calculator with some handy variables. To see a list of variables run /calc variables.

Usage: /calc <expression>

When given a rate of items per hour (expressions allowed), returns the minimum number of item sorters needed to sort in time.
Additional input for multiple times hopper speed sorters, and a separate command for Allay based non stackable sorters.

Usage: /calc storage <itemsPerHour>
Usage: /calc storage <timesHopperSpeed> <numberOfItems>
Usage: /calc allaystorage <itemsPerHour>

When given an amount of a recipe to craft (expressions allowed), returns all the items required to craft that quantity of the recipe.

(1.3.2+) The optional depth argument specifies how many levels of recursive crafting to perform on the recipe. Default depth is 1.

Usage: /calc craft <item> <amount>
Usage: /calc craft <item> <depth> <amount>

When given a block position, returns the dimension in the command's corresponding coordinates. If no coordinates are given, command assumes current player position.

Usage: /calc nether <x> <y> <z>
Usage: /calc overworld <x> <y> <z>

When given an amount of items and a farm run time in seconds (expressions allowed), returns the items per hour of the farm.

Usage: /calc rates <numberOfItems> <seconds>

When given a maximum and/or minimum value, returns a random number between those values (inclusive). If just a maximum value is entered, picks a random number from 0 to the max value (inclusive).

Usage:/calc random <max>
Usage: /calc random minmax <min> <max>

When given a container and a desired comparator power level (expressions allowed), returns the number of items needed to achieve that power level.

Usage: /calc signaltoitems <container> <powerLevel>

Calculates the average number of gold ingots needed to barter for a specific quantity of a desired item (togold), or the average number of a desired item received when bartering a specific number of gold ingots (toitem).

Usage: /calc barter togold <numberOfItems> <item>
Usage: /calc barter toitem <amountOfGold> <item>

Custom functions are reusable commands that perform a specific computation. Custom functions can be run in any number field formatted with the function name and the parameters in parentheses functionName(param1, paramN).

Creating a Function:
Custom functions can have any number of parameters, specified in [square] brackets when adding a function.

e.g. /calc custom add blockstoingots [numBlocks]*9

/calc blockstoingots(72)

Usage: /calc custom add <functionName> <function>
Usage: /calc custom run <functionName> <input>
Usage: /calc <functionName>(<parameters>)
Usage: /calc custom list
Usage: /calc custom remove <functionName>

When given an amount of full shulker boxes (expressions allowed), returns the number of items they contain, or vice versa.

Usage: /calc itemtosb <numberOfItems>
Usage: /calc sbtoitem <numberOfSbs>

When given an amount of stacks (expressions allowed), returns the number of items in those stacks, or vice versa.

Usage: /calc itemtostack <numberOfItems>
Usage: /calc stacktoitem <numberOfStacks>

When given a time in seconds (expressions allowed) returns the number of items to put in a hopper clock to achieve that time.
Uses formula and hopper clock from hoppertimer.net.

Usage: /calc secondstohopperclock <seconds>

When given a time in seconds (expressions allowed), returns the number of repeaters and their delays to achieve that time.

Usage: /calc secondstorepeater <seconds>

There are some extra mathy variables listed in this spreadsheet