Reference · Flowchart symbols
Flowchart process symbol: the rectangle, flow lines and connectors
In short
The rectangle is the flowchart process symbol: one action, operation or step. A rectangle with double vertical sides is a predefined process, a step defined in detail elsewhere. Control passes from one step to the next along flow lines (arrows). Circles are on-page connectors and pentagon shapes are off-page connectors, used to continue a flow without drawing a long line.
Updated · by the ChartCraft team · part of the flowchart symbols reference
Which flowchart symbol is used to signify a process?
The rectangle. It holds one action written as a short verb phrase ("Check stock", "Calculate tax") and has one arrow in and one arrow out. ISO 5807 names it the process symbol. Everything that is not a decision, an input/output or a start/end is normally a process.
| Symbol | Name | Meaning | Example label |
|---|---|---|---|
| Process | One action, operation or calculation | Calculate total | |
| Predefined process | A named sub-process or subroutine defined elsewhere | Validate address | |
| Flow line | Direction of flow; passes control to the next symbol | (an arrow) | |
| On-page connector | Continues the flow at the matching label on the same page | A | |
| Off-page connector | Continues the flow on another page | To page 2 |
Which flowchart symbol signifies control passing between stages of an algorithm?
The flow line, an arrow connecting two symbols. It shows which step runs next, so it is what passes control from one stage of an algorithm to the next. Arrowheads are required whenever the direction is not obvious (left to right and top to bottom are the defaults). A flow line can leave a decision on several branches, but it can leave a process on only one.
- Direction. Draw arrows pointing at the next step; a flow line without an arrowhead is read top-to-bottom or left-to-right.
- No crossings if possible. When two lines must cross, use a connector pair instead of a tangle.
- Joining. Several lines may enter one symbol, but a process still has only one exit.
- Labels. Only lines leaving a decision need labels.
What is the predefined process symbol?
A predefined process is a rectangle with a double line on each vertical side. It stands for a step whose details are defined elsewhere, such as a function, a subroutine or another flowchart. Use it to keep the main chart readable and to show reuse: many boxes can call the same predefined process.
| Process | Predefined process | |
|---|---|---|
| Shape | Plain rectangle | Rectangle with double vertical sides |
| Detail | Fully described by its label | Detailed in a separate chart or routine |
| Example | Add tax to total | Calculate tax (see tax flowchart) |
| Mermaid | A[Add tax] | A[[Calculate tax]] |
What are on-page and off-page connectors?
A connector continues a flow without a line. An on-page connector is a small circle with a letter or number, repeated on the matching circle elsewhere on the same page. An off-page connector is a pentagon (a box with a pointed bottom) used when the flow continues on another page, and carries the page or reference.
| Connector | Shape | Use | Label |
|---|---|---|---|
| On-page | Circle | Avoid long or crossing lines on one page | A, B, 1, 2 |
| Off-page | Pentagon | Continue on a different page or sheet | Page number or reference |
Terminators and connectors are different: the terminator guide explains why.
What does a chart made of process symbols look like?
A sequence of process rectangles joined by flow lines is the simplest flowchart. Each rectangle is one action, and the arrows pass control down the chart.
flowchart TD
S([Order received]) --> A[Check stock]
A --> B[Take payment]
B --> C[Pack items]
C --> D[[Ship order]]
D --> X([Order shipped])How should you label a process symbol?
Use a short verb followed by an object, and keep to one action per box. Avoid yes/no questions, which belong in a diamond.
- Good: "Check stock", "Send invoice", "Set total to 0".
- Too vague: "Process order" (split it or make it a predefined process).
- Wrong symbol: "Is stock available?" is a decision.
What do real flowcharts with these symbols look like?
Live diagrams from the public ChartCraft gallery, each generated from a plain-English description. Open one to see the prompt that produced it.
Questions
Which flowchart symbol is used to signify a process?
The rectangle. It holds one action, operation or step and has one arrow in and one arrow out.
Which flowchart symbol signifies control passing between stages of an algorithm?
The flow line, an arrow that connects one symbol to the next and shows which step runs next.
What is a predefined process in a flowchart?
A rectangle with double vertical sides that stands for a step defined elsewhere, such as a subroutine or another flowchart.
What is the difference between a process and a predefined process?
A process is fully described by its label. A predefined process refers to detail that is drawn or written somewhere else.
What is an off-page connector?
A pentagon-shaped symbol that continues the flow on another page, labelled with a page number or reference.
What is an on-page connector?
A small circle with a label that links two points on the same page without a long or crossing flow line.
How many arrows can leave a process symbol?
One. If the flow splits, add a decision (diamond) so the branches are explicit.