3D references
3D references address the same cell or range across a span of worksheets at once, written as a sheet range such as Jan:Dec!B2.
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The concepts behind formulas that work
Short, sourced explainers of the terms you meet when you build and maintain spreadsheets — and how Formula Foundry handles each one.
Cell references & names
How a formula points at cells, ranges, names and tables, and what happens to those pointers when the formula is copied.
Absolute references
Absolute references are cell addresses locked with dollar signs, such as $A$1, so the row and column stay fixed when the formula is copied.
Excel tables
Excel tables are ranges converted into a structured object that grows automatically and lets formulas address its columns by name.
Named ranges
Named ranges are labels attached to a cell or range so a formula can refer to a name such as VatRate instead of an address like $B$2:$B$40.
Structured references
Structured references address an Excel table by table and column name, such as Table1[Amount], instead of by the cell addresses underneath it.
Formulas, functions & operators
What a formula is made of: functions and their arguments, the operators that join them, and the logic they evaluate.
Boolean logic
Boolean logic is the TRUE/FALSE arithmetic behind every logical test in a formula, from a single comparison to a nested chain of IF conditions.
Function arguments
Function arguments are the inputs a function takes inside its parentheses, in a fixed order, some of them required and some of them optional.
INDEX MATCH
INDEX MATCH is a two-function lookup technique that finds a value by row and column position instead of counting columns the way VLOOKUP does.
Operators and precedence
Operators and precedence are the symbols a formula calculates with and the fixed order a spreadsheet applies them in before returning a result.
Spreadsheet functions
Spreadsheet functions are the built-in, named calculations a formula can call, each taking a defined set of arguments and returning one result.
The formula bar
The formula bar is the strip above the grid that shows what a selected cell actually contains, rather than the value the cell displays.
Variables in formulas
Variables in formulas are named values defined once and reused across a calculation, through LET, a named cell, or a tool's own variable syntax.
Wildcards
Wildcards are placeholder characters that let a formula match part of a text value instead of requiring the whole thing to be identical.
Arrays, calculation & performance
How a workbook recalculates, how array formulas spill across a range, and what makes a large model slow.
Calculation mode
Calculation mode is the workbook setting that decides whether a spreadsheet recalculates its formulas automatically or only when it is told to.
Dynamic arrays
Dynamic arrays are formulas that return many values at once and fill the neighbouring cells automatically, with no Ctrl+Shift+Enter needed.
Spill ranges
Spill ranges are the blocks of cells a single dynamic array formula fills automatically, outlined in blue and driven by one formula in the top cell.
Volatile functions
Volatile functions are functions that recalculate on every change anywhere in the workbook, whatever their inputs did — NOW, TODAY, OFFSET and others.
Errors & auditing
Why a formula returns an error value, and how to trace a workbook back to the cell that caused it.
Circular references
Circular references are formulas that depend, directly or through a chain of cells, on the cell they sit in, so the workbook cannot finish calculating.
Formula auditing
Formula auditing is the practice of tracing how a workbook calculates, using precedent and dependent arrows, formula evaluation and error checking.
Formula errors
Formula errors are the hash-prefixed values a spreadsheet returns when a formula cannot produce a result, such as #REF!, #VALUE! and #N/A.