Flowchart Symbols and Meanings: A Complete Visual Guide

Flowchart symbols are a small, standardised vocabulary: a rounded rectangle starts and ends the flow, a rectangle is an action, a diamond is a decision, a parallelogram is data going in or out, a cylinder is stored data, and a circle is a jump to somewhere else on the page. Those six carry the overwhelming majority of real charts. The rest of the standard set exists for cases where the shape genuinely tells the reader something the label cannot.

Live interactive diagramUse the player controls to follow the steps

The month-end closePlaying silently in this guideWatch with narrationOpen in editor

What this diagram shows

1. A rounded terminator opens the chart: the accounting period ends.
2. Four rectangles follow — cut off transactions, reconcile bank and control accounts, post accruals and prepayments, reconcile sub-ledgers to the general ledger.
3. A diamond asks whether the balances agree; if not, a rectangle investigates and fixes variances, then returns to the flow.
4. A document shape marks the drafted financial statements — an output, not an action.
5. A second diamond asks whether the controller approves; a rejection loops back through amend and re-review.
6. A closing terminator ends the chart: books closed and reported.

Why the shape matters at all

A shape is a promise that the reader can check at a glance. Diamonds mean "the path forks here", so a reader scanning a chart for its branches looks only at diamonds. The moment one decision is drawn as a rectangle, that shortcut stops working — and because the reader cannot tell which chart is trustworthy, it stops working everywhere.

The vocabulary was standardised by ANSI in the 1960s and internationally in ISO 5807:1985, which covers symbols for data, program and system flowcharts. It has been reviewed and confirmed since, and it is still what readers recognise.

A shape you cannot explain is worse than a rectangle. Rectangles are honest about saying nothing.

The six that carry almost every chart

• Terminator — rounded rectangle / stadium. Where the process starts and where it ends. Every chart needs one start and at least one end. Label them with the event, not the word: Offer accepted, not Start.
• Process — rectangle. An action; something gets done. Label it verb-first: Send the offer, not Offer. This is the default, and most shapes in most charts are this one.
• Decision — diamond. A question, with one labelled line leaving it per answer. If the exits are unlabelled, the symbol is doing nothing.
• Input / output — parallelogram. Data entering or leaving the process. Use it when the data itself is part of the story, not for every step that happens to touch a form.
• Data storage — cylinder. Something is written down or read back — a database, a record, a file that outlives the process.
• Connector — small circle. A labelled on-page jump, so a long path does not need an arrow dragged across the whole diagram. The label is the point: the matching circle elsewhere carries the same one.

The specialist symbols, and when they earn their place

Symbols about who or what does the work

• Predefined process — rectangle with double side bars. A sub-process defined elsewhere. This is the pressure valve for an overgrown chart: collapse a region into one of these and give it its own diagram.
• Manual operation — trapezoid. A step a person does rather than a machine. Worth using in an automation review, where "which steps are still manual?" is the entire question.
• Manual input — a rectangle with a sloped top. Data typed in by a person, as opposed to arriving from a system.
• Preparation — hexagon. Setup or initialisation before the main flow: seeding a value, opening a session.

Symbols about data and documents

• Document — rectangle with a wavy base. A single document or printed report produced or consumed. In a finance chart this is often the most useful non-core symbol you have, because the output is the deliverable.
• Internal storage — a rectangle with an inset corner rule. Memory or an in-process data structure, as distinct from a database that outlives the run.
• Display — a rounded, screen-like shape. Something shown to a person on a screen.
• Card. A punch card: one record of input. Genuinely archaic, and it is in the standard set for historical reasons rather than because your process needs it.

Symbols about time, loops and merging

• Delay — a D-shape. A wait before continuing. In a process being measured for cycle time, this is where the time actually goes, and drawing it makes that visible.
• Loop limit — a shape with clipped top corners. The bound of a loop and its limit condition.
• Or — a circle with a cross. Paths merge, and any one of them continues the flow.
• Summing junction — a circle with an X. Paths combine into one. Distinct from Or: this one means all of them, that one means any.
• Off-page connector — a home-plate pentagon. A jump to another page of the same flow. If you need many of these, the chart wants splitting into sub-processes instead.

All of these are in the shapes panel of the flowchart editor, grouped so the six core shapes are the ones you reach first.

A worked example: reading the symbols in a month-end close

The chart at the top of this page uses five distinct symbols, and each one is doing a job.

It opens and closes on terminators — the accounting period ending, and the books being closed and reported. Between them, four rectangles carry the ordinary work: cut off transactions, reconcile bank and control accounts, post accruals, reconcile sub-ledgers. Two diamonds mark the only two places where the chart can go somewhere other than forwards: Do the balances agree? and Approved by the controller? Both have a labelled loop back into the flow.

And there is one document: the drafted financial statements. That shape is the reason the chart is worth reading twice. Everything else on the page is an action; the document is the artefact the whole month produces, and giving it its own shape says so without a word of explanation.

Charts that use the vocabulary properly

Open any of these and inspect the shapes — they are editable diagrams, not pictures.

Symbols people get wrong

• Ovals for everything rounded. A terminator is a stadium (a rectangle with semicircular ends), not a circle. A circle is a connector. Drawing terminators as circles quietly collides with the connector symbol.
• Diamonds with unlabelled exits. The commonest defect in charts that reach review, and the one that costs the reader the most.
• Parallelograms for any step involving a form. Input/output means data crosses the process boundary, not that a form was touched.
• Cylinders used as decoration for "the system". A cylinder means stored data. If you mean a service, draw an architecture diagram instead.
• Off-page connectors as a layout fix. They are for genuinely multi-page flows. Used to escape a cramped canvas, they hide the very structure the chart exists to show.
• Colour used as a second notation. Shape carries meaning; colour should reinforce it, never replace it. A reader who is colour-blind, or reading a printed copy, still needs the chart to work.

Best practices

• Use the six core shapes by default. Reach for a specialist symbol only when you can say what it tells the reader that a label would not.
• Be consistent within one chart. One symbol, one meaning, throughout. Inconsistency is more damaging than using a plain rectangle everywhere.
• Add a legend for anything unusual. If you use a loop limit or a summing junction, spend one line saying so.
• Keep sizes uniform. A bigger box reads as a more important step whether or not you meant it.
• Match the symbol set to the audience. An operations team reading a chart once does not need punch cards; an engineer reviewing a legacy system flow might genuinely need internal storage.

When flowchart symbols are not enough

The flowchart vocabulary describes what happens next. It has no way to say who owns a step, and no formal execution semantics. Two things to reach for when you hit that ceiling:

• To show ownership and handoffs, put the same flow into lanes — see how to create a swimlane diagram.
• To describe a workflow at the level of stages rather than individual actions, use a process flow diagram.
• For formal, executable process modelling — typed events, gateways, message flows — the standard is BPMN, specified by the OMG as BPMN 2.0.2.

In short

Six symbols do almost all the work: terminator, process, decision, input/output, data storage and connector. The rest of the standard set is there for the moments when the shape genuinely says something — a document that is the deliverable, a delay that is where the time goes, a manual operation in a chart about automation. Use those deliberately, use the core six by default, and never use a shape you would struggle to explain.

Ready to build one? The flowchart editor has the whole set in its shapes panel, and the guide to creating a flowchart step by step covers the process around them.

Questions people actually ask

What does each flowchart symbol mean?

A rounded rectangle is the start or end, a rectangle is an action, a diamond is a decision, a parallelogram is data in or out, a cylinder is stored data, and a circle is a labelled jump to elsewhere in the chart. Specialist shapes cover documents, sub-processes, manual steps, delays, loops and merges.

What is the diamond shape in a flowchart?

A decision: a question with one labelled line leaving it per answer. If a diamond's exits are not labelled, it is not doing its job — a reader cannot tell which line means yes.

Is there an official flowchart symbol standard?

Yes. ISO 5807:1985 defines symbols and conventions for data, program and system flowcharts, and descends from the earlier ANSI work. Most tools follow it loosely rather than exactly, so a legend is still worth adding for uncommon shapes.

What is the difference between a terminator and a connector?

A terminator is a stadium shape marking where the whole process begins or ends. A connector is a small circle carrying a label, used to continue a path elsewhere on the page without dragging a long arrow. They are often confused because both look "round".

How many flowchart symbols do I actually need?

Usually four: terminator, process, decision and one of input/output or document. Adding shapes beyond what the chart needs makes it harder to read, not more precise.

Can I add custom shapes to a flowchart?

You can — the editor includes plain rectangles, ellipses and notes alongside the standard set. Treat that as annotation rather than notation: a custom shape carries no shared meaning, so anything it needs to say must be in its label or a legend.