# deepcalc

> The spreadsheet runtime for agents: a headless, excel-compatible calculation engine with branches, diffs and review, driven over an HTTP API and MCP. Every change is journaled, every state addressable, every merge reviewable.

Append `.md` to any page URL for a clean markdown twin, or send `Accept: text/markdown`.

## reference

- [Function reference](https://deepcalc.com/functions.md): 556 spreadsheet functions with signatures and arguments, generated from the engine catalog
- [Error values](https://deepcalc.com/errors.md): what each spreadsheet error means, why it happens, how to fix it
- [Concepts](https://deepcalc.com/concepts.md): references, array formulas, spill ranges, recalculation
- [Limits](https://deepcalc.com/limits.md): grid bounds and request caps

## function categories

- [array (30)](https://deepcalc.com/functions/array-functions.md): work on whole ranges at once and return multiple values.
- [database (14)](https://deepcalc.com/functions/database-functions.md): group, aggregate and query tabular ranges.
- [datetime (25)](https://deepcalc.com/functions/datetime-functions.md): build, read and do arithmetic on dates and times.
- [engineering (55)](https://deepcalc.com/functions/engineering-functions.md): unit conversion, bases, complex numbers and bitwise operations.
- [financial (55)](https://deepcalc.com/functions/financial-functions.md): interest, cash flow, depreciation and valuation.
- [information (21)](https://deepcalc.com/functions/information-functions.md): ask what a cell holds — type, emptiness, errors.
- [logical (11)](https://deepcalc.com/functions/logical-functions.md): branch and combine conditions.
- [lookup (13)](https://deepcalc.com/functions/lookup-functions.md): find a value in a range and return a related one.
- [math (84)](https://deepcalc.com/functions/math-functions.md): arithmetic, rounding, trigonometry and aggregation.
- [options (20)](https://deepcalc.com/functions/options-functions.md): option pricing and the greeks — deepcalc originals, no excel equivalent.
- [stats (146)](https://deepcalc.com/functions/stats-functions.md): distributions, averages, spread and regression.
- [text (59)](https://deepcalc.com/functions/text-functions.md): join, split, clean, search and format strings.
- [utility (20)](https://deepcalc.com/functions/utility-functions.md): helpers that do not belong to one calculation domain.
- [web (3)](https://deepcalc.com/functions/web-functions.md): fetch and parse data from outside the sheet.

## error values

- [#DIV/0!](https://deepcalc.com/errors/div-0.md): a formula divides by zero or by an empty cell.
- [#N/A](https://deepcalc.com/errors/na.md): a value is not available — usually a lookup that found no match.
- [#NAME?](https://deepcalc.com/errors/name.md): the formula contains text the engine does not recognise.
- [#NULL!](https://deepcalc.com/errors/null.md): two ranges were intersected but do not overlap.
- [#NUM!](https://deepcalc.com/errors/num.md): a number is invalid or the result is impossible to represent.
- [#REF!](https://deepcalc.com/errors/ref.md): a formula points at a cell that no longer exists.
- [#VALUE!](https://deepcalc.com/errors/value.md): an argument or operand has the wrong type.
- [#SPILL!](https://deepcalc.com/errors/spill.md): a formula returns multiple values but cannot write them out.
- [#CALC!](https://deepcalc.com/errors/calc.md): the calculation engine cannot produce the requested array.

## concepts

- [absolute and relative references](https://deepcalc.com/concepts/absolute-and-relative-references.md): why a reference changes when you copy a formula, and how $ stops it.
- [A1 notation](https://deepcalc.com/concepts/a1-notation.md): how cells, ranges and worksheets are addressed in a formula.
- [structural edits](https://deepcalc.com/concepts/structural-edits.md): what happens to formulas when rows or columns are inserted, deleted or moved.
- [array formulas](https://deepcalc.com/concepts/array-formulas.md): formulas that operate on many values at once and return many results.
- [spill range](https://deepcalc.com/concepts/spill-range.md): the block of cells a multi-value formula writes its results into.
- [circular references](https://deepcalc.com/concepts/circular-references.md): a formula that depends, directly or indirectly, on its own result.
- [volatile functions](https://deepcalc.com/concepts/volatile-functions.md): functions that recalculate on every change, whatever their inputs did.
- [recalculation](https://deepcalc.com/concepts/recalculation.md): how a change to one cell propagates through everything that depends on it.

## optional

- [Everything in one file](https://deepcalc.com/llms-full.txt): the whole reference concatenated