Flowchart Symbols Reference

The five core symbols are: Oval (start/end), Rectangle (process step), Diamond (decision), Parallelogram (input/output), and Arrow (flow direction). These five cover 90% of all flowcharts.

A diamond represents a decision point — a yes/no question or condition that splits the flow into two or more paths. Always label the outgoing arrows with the conditions (Yes/No, True/False, or specific values).

A standard rectangle is a process step (an action). A rounded rectangle (or oval/pill shape) is a terminal — it marks where the process starts or ends. Some tools use rounded rectangles for subroutines or predefined processes.

A parallelogram represents input or output — data entering or leaving the process. Examples: "User enters password" (input), "Display report" (output), "Print invoice" (output).

A cylinder represents a database or data storage. Use it when your process reads from or writes to persistent storage — a database, file system, or data warehouse.

A D-shape (half-oval or half-pill) represents a delay or waiting period. Examples: "Wait for approval," "Hold for 24 hours," "Queue for processing."

A small circle with a label (letter or number) that links one part of a flowchart to another without drawing a long arrow. Use connectors when your flowchart spans multiple pages or when direct arrows would create tangles.

Yes — ISO 5807 and ANSI X3.5 define standard flowchart symbols. The core shapes (oval, rectangle, diamond, parallelogram, arrow) are identical across both standards. In practice, most teams use the core five without worrying about formal compliance.