Iso 5807 Flowchart Symbol Codes Chart — Complete Reference Guide

If you've ever tried to create a flowchart that other people can actually read and understand, you've probably run into a frustrating problem: everyone uses different shapes for the same meaning. That's exactly the confusion ISO 5807 flowchart symbol codes chart was designed to fix. This standard gives you a shared visual language so that a flowchart drawn in Tokyo reads the same way in Toronto.

What exactly is the ISO 5807 flowchart symbol codes chart?

ISO 5807 is an international standard published by the International Organization for Standardization. It defines a set of symbols and conventions for data processing flowcharts, program flowcharts, system flowcharts, and other documentation diagrams used in computing and information processing.

The chart assigns specific meanings to specific shapes. A rectangle means a process. A diamond means a decision. A parallelogram means input or output. These aren't suggestions they're standardized definitions that teams around the world agree to follow.

The standard was first published in 1985 and has remained a reference point for technical documentation, software engineering, and systems analysis ever since. You can view the official listing through the ISO catalog page for ISO 5807.

Why does having a standardized flowchart symbol chart matter?

Without a shared standard, flowcharting becomes a guessing game. One developer's "start" oval might look like another person's "connector" circle. A box that means "process" in one diagram might mean "subroutine" in another.

Standardized symbols solve three real problems:

Miscommunication between teams When a systems analyst hands a flowchart to a programmer, both need to agree on what each shape means. ISO 5807 provides that agreement without lengthy explanations.
Documentation consistency Organizations that maintain large codebases need flowcharts that look and read the same way across projects, teams, and years.
Auditing and compliance In regulated industries, documentation often needs to follow recognized standards. ISO 5807 gives your flowcharts a credible foundation.

What symbols are included in the ISO 5807 chart?

The standard defines symbols across several categories. Here are the most commonly used ones:

Basic process symbols

Rectangle (Process) Represents a single operation or step, such as "Calculate total" or "Sort list."
Diamond (Decision) Shows a point where the flow branches based on a yes/no or true/false condition.
Parallelogram (Input/Output) Indicates data entering or leaving the process, like reading a file or printing a report.
Rounded rectangle or oval (Terminal) Marks the start or end of a flowchart.
Arrow (Flow line) Connects symbols and shows the direction of the process flow.

Advanced and specialized symbols

Predefined process A rectangle with double vertical edges, pointing to a process defined elsewhere.
Manual operation A trapezoid, indicating a step performed by a person rather than a machine.
Document A rectangle with a wavy bottom edge, representing a printed document or report.
Connector A small circle used to link different parts of a flowchart, especially when lines would otherwise cross or the chart spans multiple pages.
Storage Represents data stored on a medium like a disk or database.

If you're just getting started with these shapes, our guide on flowchart symbol codes for beginners walks through each one with visual examples.

How does ISO 5807 compare to ANSI flowchart symbols?

ISO 5807 and ANSI flowchart symbol codes overlap significantly because ANSI standards influenced the ISO document. Many of the basic shapes are identical in both systems. The main differences show up in specialized symbols ISO 5807 includes more symbols for data processing environments, such as specific storage and communication link indicators.

In practice, most professionals working in North America encounter ANSI symbols first, while those working on international or ISO-compliant projects follow ISO 5807. If your organization works across both contexts, it helps to know where the two sets align and where they differ.

When would you actually use the ISO 5807 flowchart symbol codes chart?

You reach for this standard whenever clear, unambiguous process documentation matters. Common scenarios include:

Software development Mapping out algorithms, program logic, and system architecture before writing code. Our resource on standard flowchart symbol codes in programming covers this use case in detail.
Business process mapping Documenting workflows like order fulfillment, customer onboarding, or approval chains so that new employees can follow them without guesswork.
Systems analysis Showing how data moves through a system, where decisions are made, and what outputs are produced.
Quality management Creating controlled documentation for ISO 9001 or other quality frameworks that reference process documentation.
Education and training Teaching students or new hires the fundamentals of structured programming and logical thinking.

What are common mistakes people make with ISO 5807 symbols?

Even experienced professionals trip up on a few recurring issues:

Mixing symbol standards in one diagram Using an ANSI connector in a chart that otherwise follows ISO 5807 creates confusion. Pick one standard and stick with it.
Using the wrong shape for decisions Some people use rectangles with text like "If X then Y" instead of the diamond shape. The diamond exists specifically to flag branching logic at a glance.
Overloading process boxes A process symbol should represent one clear action. If you're writing three sentences inside a single rectangle, break it into multiple steps.
Forgetting flow direction Flowcharts should read top-to-bottom or left-to-right. Arrows going in random directions make a chart hard to follow.
Skipping the terminal symbol Every flowchart needs a clear start and end point. Leaving these out forces readers to guess where the process begins and ends.

How do you read an ISO 5807 flowchart symbol codes chart quickly?

A practical shortcut: memorize the five core shapes first (terminal, process, decision, input/output, and flow line). These cover about 80% of any standard flowchart you'll encounter. The remaining specialized symbols manual operations, predefined processes, documents, connectors you can look up as needed.

When reading an existing flowchart, start at the terminal marked "Start" and follow the arrows. At each decision diamond, note the condition and which path you'd take. This simple walk-through approach works whether the chart uses five symbols or fifteen.

What are some useful tips for applying ISO 5807 in real work?

Keep a printed reference chart at your desk or bookmarked in your browser. You shouldn't have to memorize every symbol to use the standard effectively.
Use consistent sizing All process boxes should be roughly the same size. Avoid making some symbols tiny and others huge unless the visual difference carries meaning.
Label every decision branch Always write "Yes/No" or the specific condition on each arrow leaving a decision symbol.
Test your flowchart with someone unfamiliar with the project If they can follow it without your explanation, the symbols are doing their job.
Use software that supports ISO 5807 symbols Tools like draw.io, Lucidchart, Microsoft Visio, and yEd include ISO-compliant symbol libraries.

What should you do next?

If you're ready to start using ISO 5807 flowchart symbols in your own work, here's a practical checklist to follow:

Print or bookmark an ISO 5807 symbol reference chart for quick lookup.
Pick your flowcharting tool and confirm it includes ISO-compliant symbol libraries.
Start with the five core symbols: terminal, process, decision, input/output, and flow line.
Draft a simple flowchart for a process you know well a morning routine works fine for practice.
Have someone else review your flowchart to check for clarity.
Compare your chart against the ANSI equivalents if you work in mixed-standard environments.
Gradually add specialized symbols (document, manual operation, predefined process) as your flowcharts grow more detailed.

Getting comfortable with these symbols takes a few practice diagrams, not weeks of study. The sooner you start applying them, the faster they become second nature.