# recalculation

how a change to one cell propagates through everything that depends on it.

A spreadsheet is a dependency graph: each formula knows which cells it reads. When a value changes, the engine walks the graph and recomputes only what depends on it, in dependency order, rather than recalculating the whole sheet.

This is why the order of cells on screen does not matter, and why a circular dependency is fatal — the graph must have an order to walk.

deepcalc recomputes per branch head, and diffs the outputs rather than storing them as truth. That is what makes it possible to show only the values that actually moved after an edit, instead of every cell the engine happened to touch.

## related

circular references · volatile functions

## navigate

- [all concepts](https://deepcalc.com/concepts.md)
- [function index](https://deepcalc.com/functions.md) · [error values](https://deepcalc.com/errors.md) · [limits](https://deepcalc.com/limits.md)

source: https://deepcalc.com/concepts/recalculation