April 21, 2026Updated July 18, 2026 11 min readFreeFlowCharts Team

Flowchart Symbols and Their Meanings: The Definitive Guide

Complete reference to flowchart symbols: terminator, process, decision, I/O, subprocess, delay, database, swimlanes, and color-coding best practices with examples.

symbols guide reference flowchart

Understanding flowchart symbols is essential for creating and reading flowcharts. Each shape has a specific meaning defined by international standards (ISO 5807). This guide covers every symbol you'll encounter, with examples and best practices.

Standard flowchart symbols

#### Oval — Start / End (Terminator)

The oval (or rounded rectangle) marks the beginning and end of a flowchart. Every flowchart must have at least one start and one end terminator.

Use "Start" or a specific trigger ("User clicks Submit") for the entry point

Use "End" or a specific outcome ("Order Confirmed") for exit points

A flowchart can have multiple end points but typically only one start

#### Rectangle — Process

The rectangle is the most common flowchart symbol. It represents a single action or operation.

Examples: "Calculate total", "Send email", "Update database"

Keep labels short — one action per rectangle

If a step is complex, use a subprocess symbol instead

#### Diamond — Decision

The diamond represents a decision point with two or more outcomes. This is where the flow branches.

Always phrase as a question: "Is the order over $100?", "Did the test pass?"

Label each exit arrow with the answer: "Yes" / "No", or specific values

Avoid more than 3-4 exits from a single decision — use multiple decisions instead

#### Parallelogram — Input / Output

The parallelogram represents data entering or leaving the system.

Input examples: "User enters email", "Scan barcode", "Upload file"

Output examples: "Display results", "Print report", "Send notification"

Use this when the step specifically involves data transfer

#### Rectangle with double lines — Subprocess (Predefined Process)

A subprocess symbol indicates a process that's defined in detail elsewhere (another flowchart or document).

Examples: "Run payment processing", "Execute validation routine"

Use when a step is too complex for a single rectangle but you don't want to clutter the main flow

Link to the detailed sub-flowchart if possible

Extended flowchart symbols

#### Circle with arrow — Delay / Wait

Represents a waiting period in the process.

Examples: "Wait 24 hours", "Await approval", "Queue for processing"

Useful for processes with built-in delays or SLAs

#### Hexagon — Preparation

Indicates a setup or preparation step.

Examples: "Initialize variables", "Set up test environment"

Less common in business flowcharts, more common in programming

#### Document shape — Document

Represents a document or report generated or used in the process.

Examples: "Generate invoice", "Read configuration file"

#### Cylinder — Database / Data Store

Represents stored data.

Examples: "Customer database", "File system", "Cache"

Annotation symbols

#### Sticky Note

A comment or note attached to the flowchart for clarification. Doesn't affect the flow.

#### Text Label

A free-text label for grouping or annotating sections of the flowchart.

#### Swimlane

A horizontal or vertical lane that groups steps by responsibility (team, person, or system). Swimlanes make it clear who does what.

Color coding best practices

While not part of the standard, color coding dramatically improves readability:

Green: Start nodes, successful outcomes, approvals

Red: End nodes, errors, rejections

Blue: Standard process steps, automated actions

Orange/Yellow: Decision points, warnings, manual steps

Purple: Input/Output, data operations

Gray: Delays, waiting periods

Quick reference table

Oval — Start or End of the process

Rectangle — Action or process step

Diamond — Decision (yes/no or branching)

Parallelogram — Data input or output

Double-lined rectangle — Subprocess or predefined process

Circle — Delay or wait

Hexagon — Preparation step

Document shape — Document or report

Connecting symbols (flow lines)

Arrows are symbols too. Rules that keep charts readable:

One primary direction (top→bottom or left→right)

Arrow labels only where meaning is not obvious (always on decision exits)

Avoid crossing lines; reroute or split into a subprocess

Merge paths with clear join points rather than ambiguous overlaps

Symbols FreeFlowCharts maps to node types

In the flowchart editor you will find practical node types aligned to these standards plus product-oriented nodes (task, bug, email, meeting, approval, milestone, deadline, handoff, cost, sticky note, swimlane). Use standard shapes for external audiences; use specialized nodes when your internal team benefits from the extra semantics.

Example: symbols in a login flow

Oval: Start — User opens login page

Parallelogram: Enter email and password

Rectangle: Validate credentials

Diamond: Valid?

Rectangle: (Yes): Create session

Parallelogram: (No): Show error message

Oval: End — Dashboard / End — Retry

Teaching tip

When onboarding junior analysts, print a one-page symbol legend next to the chart for the first month. Consistency beats creativity: a team that invents custom shapes slows every new reader.

Related guides

How to make a flowchart

Decision tree flowchart guide

Free flowchart maker overview

Create flowcharts with proper symbols

FreeFlowCharts includes standard flowchart symbols plus practical node types — drag them from the sidebar onto the canvas. Each node type is color-coded so you pick the right shape for the job.