Flowchart Shapes Guide

Core Flowchart Shapes

Oval / Rounded Rectangle

TERMINATOR

Marks the beginning or end of the entire flowchart. Every flowchart must have exactly one Start and at least one End (also called "Stop" or "Exit").

Examples: "Start", "Begin", "End", "Stop", "Exit Program"

Rectangle

PROCESS

Represents an action, task, or operation being performed. This is the most common shape in any flowchart. It does something — calculates, assigns, moves, prints, etc.

Examples: "Add 1 to counter", "Save file", "Send email", "Calculate total"

Diamond

DECISION / BRANCH

A question or condition that creates a fork in the flow. It always has 2 or more exits — typically labeled Yes/No or True/False. The flow takes different paths based on the answer.

Examples: "Is x > 10?", "Password correct?", "File found?"

Parallelogram

INPUT / OUTPUT (I/O)

Represents data entering or leaving the system. Input: reading data (keyboard, file, sensor). Output: displaying or printing data (screen, report, file). The same shape is used for both.

Examples: "Read user name", "Print invoice", "Get temperature", "Display result"

Document Shape

DOCUMENT

Represents a physical or digital document being created, read, or referenced. The wavy bottom edge distinguishes it from a plain rectangle. Used in business workflows more than coding flowcharts.

Examples: "Print report", "Generate PDF invoice", "Read instruction manual"

Rectangle with Double Side Bars

SUBROUTINE / PREDEFINED PROCESS

Calls a separate process, function, or module that is defined elsewhere. This avoids redrawing complex logic by simply referencing the named procedure. The vertical bars on both sides signal "this step expands into its own flowchart."

Examples: "validateLogin()", "calculateTax()", "sendEmail()"

Cylinder

DATABASE / STORED DATA

Represents data storage — a database, disk, file system, or any persistent store. Used whenever data is read from or written to a storage system.

Examples: "Query customer DB", "Write log to disk", "Fetch from cache"

Slanted-Top Rectangle

MANUAL INPUT

Specifically indicates a human manually entering data, such as typing on a keyboard. Distinguished from a plain I/O parallelogram by the slanted top edge.

Examples: "User types password", "Operator enters quantity"

Circle / Small Circle

CONNECTOR / ON-PAGE REFERENCE

Used when a flow line needs to continue somewhere else on the same page to avoid messy crossing lines. Two circles with the same letter/number are connected — one exits, one enters at a different location.

Examples: "A" circle leading from one column to another column on the same page

Pentagon / Home Plate

OFF-PAGE CONNECTOR

Connects to a matching shape on a different page of a multi-page flowchart. Prevents flow lines from spanning multiple pages. The matching label (letter/number) identifies the pair.

Examples: Flow continues on "Page 2, Shape B"

D-Shape / Half-Oval

DELAY

Represents a deliberate pause or wait period in the process — waiting for a timer, approval, external event, or resource availability. Common in manufacturing and business workflows.

Examples: "Wait 24 hours", "Await approval", "Sleep 5 seconds"

Hexagon

PREPARATION / INITIALIZATION

Indicates a setup step or loop initialization — setting a variable before a loop begins, configuring environment, or any preparatory step distinct from a regular process.

Examples: "Set counter = 0", "Initialize array", "Open connection"

Arrows & Flow Lines

Types of Connecting Lines

Arrows show the direction of flow between shapes. Never draw a flowchart without clear arrowheads!

Solid Arrow

Normal flow direction

Dashed Arrow

Optional / conditional path

Curved Arrow

Loop back / return path

Bidirectional Arrow

Two-way data exchange

Quick Reference Table

Shape	Name	Used For	Tip
Oval	Terminator	Start / End	Every flowchart needs exactly one Start
Rectangle	Process	Action / Computation	Most frequently used shape
Diamond	Decision	Yes/No question	Always label both exit paths
Parallelogram	I/O	Input or Output	Same shape for both read and write
Document	Document	Reports, files	Common in business flowcharts
Double-bar rect	Subroutine	Call a function	Defined in a separate flowchart
Cylinder	Database	Stored data	Think "hard drive / database"
Slanted-top rect	Manual Input	Human keyboard entry	Specifically for human interaction
Small Circle	On-page Connector	Continue on same page	Avoids crossing lines
Pentagon	Off-page Connector	Continue on another page	Use matching labels (A, B, 1, 2…)
D-Shape	Delay	Wait / pause	Common in manufacturing flows
Hexagon	Preparation	Loop setup / init	Sets variables before loops

Example: Login Process Flowchart

See How the Shapes Work Together

This diagram shows a typical user login process using the shapes described above.

Reading the example: Start at the oval → Input credentials (parallelogram) → Call validateCredentials() subroutine (double-bar rectangle) → Decision diamond asks if valid → NO loops back to re-enter (red arrow) → YES continues down → Load dashboard (rectangle) → Fetch from database (cylinder) → Display result (parallelogram) → End (oval).

Golden Rules for Students

#	Rule	Why it Matters
1	Always use an oval for Start and End	Without terminators, the flow has no defined entry/exit point
2	Label both exits of every diamond	An unlabeled branch causes confusion about which path to take
3	Flow should generally go top-to-bottom or left-to-right	Makes the diagram intuitive and easy to follow
4	Use arrowheads on every line	Without arrows, the direction of flow is ambiguous
5	One shape = one action or one decision	Crowding too many things into one shape loses clarity
6	Use connectors instead of crossing lines	Crossed lines are confusing and look unprofessional
7	Keep text inside shapes short and clear	Long text makes shapes hard to read at a glance