Measuring Distances on a PCB

Designing a printed circuit board is all about accurate sizes and exact measurements. Objects are carefully defined at precise sizes, and accurately placed within the design space. Everything about the printed circuit board requires careful configuration and placement.

Measurements can be performed in either 2D mode, or

3D mode, and the display of the results remain until cleared.

 

The PCB editor supports two styles of measurement, in each of the editing modes:

  • 2D editing mode you can: measure the distance between any two points in the editing space, or the distance between any two objects.

  • 3D editing mode you can: measure the distance between any two 3D objects, or the distance between two recognized reference points on 3D objects.

Measuring in the PCB Editor

The PCB editor relies on the Unified Cursor-Snap System to locate the cursor in the editing space. Cursor snap occurs when you are taking measurements, playing a fundamental role during the measurement process. For this reason, it is important to understand how to control and configure cursor snapping during editing.

There are two core aspects to the cursor-snap system, what the cursor snaps to, and when it will snap.

  • What - the points in space that the cursor snaps to include: user-defined Grids, work Guides, and snap points on the Objects.

  • When - the cursor snaps to a snap point: when it is within the Snap Distance, and snapping is allowed on that Layer.

A demonstration of various Cursor-Snap behaviors.

Fluency in the PCB editor improves when you can control and configure the cursor-snap system while you work. Learn more about Interactively Controlling the Snap Behavior.

Measure Distance between Two Points in 2D

To measure and display the distance between any two points in the current document:

Measuring the distance between two points.

  1. Select the Reports » Measure Distance command from the main menus (shortcut: Ctrl+M). The cursor changes to a cross-hair as you enter measurement mode.

  2. The Status bar prompts: Select Measure Start Point. Position the cursor on the point where you want to start measuring, then click or press Enter.

  3. Move the cursor to the required end point and click, or press Enter again. As you move the cursor, a measuring line is displayed as an aid.

  4. The Measure Distance dialog appears (), reporting: the point-to-point distance, the X (horizontal) distance, and the Y (vertical) distance, in both metric (mm) and imperial (mil) units. To copy the contents of the dialog to the Windows Clipboard, press Ctrl+C.

  5. The measurement is also displayed visually within the design space, showing the measurement's X, Y, and direct distances. The direct (shortest) distance is shown in yellow, with the X and Y distances in light blue. To toggle the results between metric and imperial, press the Q shortcut key.

  6. The measurement is also displayed in the Messages panel. Double-click on a result in the panel to return to an earlier measurement, and have its measurement lines displayed again in the design space. The zoom level is configured in the System – Navigation page of the Preferences dialog ().

  7. Continue measuring the distance between other points, or right-click or press Esc to exit measurement mode.

  8. To clear previous measurements from the design space, press Shift+C.

Measure Distance between Two Primitive Objects in 2D

To measure and display the distance between the edges of any two primitive objects in the current document:

Measuring the distance between two primitives.

  1. Select the Reports » Measure Primitives command from the main menus. The cursor changes to a cross-hair as you enter measurement mode.

  2. The Status bar prompts: Choose First Primitive. Position the cursor anywhere over the first primitive, then click or press Enter. To be able to select a primitive using this command, that primitive type must be enabled in the Selection Filter ().

  3. Move the cursor anywhere over the second primitive, then click or press Enteragain.

  4. The Clearance dialog appears (), reporting the smallest clearance between the two chosen primitives, which may not be at the location where you clicked. The dialog also contains information on the layer and location for each of the primitives. To copy the contents of the Clearance dialog to Windows Clipboard, press Ctrl+C.

  5. The measurement is also displayed visually within the design space, showing the measurement's X, Y, and direct distances. The direct (shortest) distance is shown in yellow, with the X and Y distances in light blue. To toggle the results between metric and imperial, press the Q shortcut key.

  6. The measurement is also displayed in the Messages panel. Double-click on a previous measurement result in the Messages panel to cross-probe to that measurement and have its measurement lines displayed again in the design space. The zoom level is configured in the System – Navigation page of the Preferences dialog ().

  7. Continue measuring the distance between other primitives, or right-click or press Esc to exit measurement mode.

  8. To clear previous measurements from the design space, press Shift+C.

  • When using the command between a primitive and a pad/via and the shape of this pad/via is smaller on the layer on which the first primitive is placed compared to its shape on other layers, the Clearance dialog shows the distance between primitives on the layer on which the first primitive is placed, and also the shortest XY distance between the primitives (the 'flattened' distance). In other words, the flattened distance is the distance between projections onto the XY plane of all shapes of the primitives. For example, if there is an SMT pad on the Top Layer and a via that has a larger shape on the Bottom Layer, measuring the distance between the pad and the via will show two measurements – one on the Top Layer and one between the pad and the via shape on the Bottom Layer ().

  • This command only measures the distance between primitive design objects. You cannot include group objects, such as components or dimensions, in your measurements.

Measure the Length of Selected Objects

To measure the length of selected tracks and arcs in the current design:

Measuring the length of selected tracks and arcs.

  1. Select the tracks and arcs you want to measure.

    As well as using the Connected Copper and Physical Connection commands (Edit » Select submenu), an easy way to quickly select connected objects is to select one object, and then press the Tab key to extend the selection. The first press of Tab adds touching tracks and arcs on the same layer, the second press adds all objects on the same layer, the third press adds all objects on all layers. The forth press of Tab either adds all non-touching objects on the same net to the selection set, or if there are none, returns you to the first state – the original object you selected.

  2. Select the Reports » Measure Selected Objects command from the main menus. Note that selected fills, regions, pads or vias are not included in the measurement.

  3. The Information dialog appears (), detailing the total measured length of the selected tracks and arcs. To copy the contents of the Information dialog to Windows Clipboard, press Ctrl+C.

  4. The measurement is also displayed in the Messages panel.

Measure Distance Between 3D Objects or Faces

To measure distances between 3D objects:

Perform accurate object-to-object measurements in the 3D Layout Mode. The shortest distance between the chosen objects is shown in yellow.

  1. Select the Reports » Measure 3D Objects command from the main menus. The cursor changes to a cross-hair as you enter measurement mode.

  2. Choose the first 3D object or specific face of that object. As you move the cursor over a potential 3D object, the object color changes to green. To select a specific face of the object, hold the Ctrl key as you move the cursor - the face currently under the cursor will be highlighted. When the required object/face is highlighted, click or press Enter to confirm your selection.

  3. Before you select the second object, the tool will display measurements for the shortest distance from the underside of this first object (face) to the board surface, and also the shortest distance from this first object (face) to the board edge.

  4. Position the cursor to highlight the second 3D object/face, and click or press Enter to confirm selection.

  5. The 3D Distance dialog appears (), reporting: the two 3D objects that were chosen, the shortest point-to-point distance between the objects (at the lowest possible point in the Z-plane), the X-plane (horizontal) distance, and the Y-plane (vertical) distance, in both metric (mm) and imperial (mil) units. To copy the contents of the dialog to the Windows Clipboard, press Ctrl+C.

  6. The measurements are also displayed visually within the design space, showing the X-plane, Y-plane, and direct distances. The direct (shortest) distance is shown in yellow, with the X and Y distances in light blue. To toggle the results between metric and imperial, press the Q shortcut key.

  7. The measurement is also displayed in the Messages panel. Double-click on a result in the panel to return to an earlier measurement, and have its measurement lines displayed again in the design space. The zoom level is configured in the System – Navigation page of the Preferences dialog ().

  8. Continue measuring the distance between other objects/faces, or right-click or press Esc to exit measurement mode.

  9. To clear previous measurements from the design space, press Shift+C.

  • The information about the chosen 3D object includes the Identifier of the chosen 3D Body objects (in parentheses). Having a value for the Identifier will help you know that you have clicked on the right object.

  • To calculate the object-to-object distance, the tool must first calculate the location of each of the selected objects. The results of these object-location measurements are also displayed. For the object-to-board measurements, the software calculates the distance from:

    1. the reference point on the object, to the board surface (Z measurement), and

    2. the reference point on the object, to the board edge (X or Y measurement).

    3. As with the object-to-object measurement, it also triangulates from the reference point on the object to the reference point on the board and displays this direct distance in yellow.

Measure Distance between Points on 3D Bodies

To measure distances between two points on the same 3D Body, or between points between two different 3D bodies:

Measure between 2 points on 3D objects.

  1. Switch to 3D Layout Mode (shortcut: 3).

  2. For this type of measurement, it can help to display the reference points in the 3D models, which includes the 3D Reference Points designed into the models, as well as Custom Snap Points that have been added in the PCB library editor ().

  3. Choose the Tools » 3D Body Placement » Measure Distances command from the main menus. The cursor changes to a cross-hair as you enter measurement mode.

  4. The first click is to nominate the first 3D model to be used, click anywhere on the object. As you move the 3D positional cursor around (blue, six-pointed), it will jump between the available vertices, reference points and snap points in that model ().

  5. Position the 3D positional cursor and click to nominate a vertex or snap point as the first measurement point on that 3D model.

  6. The next click can either be:

    1. Locating a vertex or snap point with the 3D positional cursor on the same 3D model, then clicking to nominate that as the second measurement point.

    2. Or you can move the small cross-hair cursor over a different 3D model, click once to nominate that model, then position the 3D positional cursor on a vertex or snap point on that second model and click again to nominate the second measurement point.

  7. An Information dialog appears () showing the direct point-to-point distance, as well as the point-to-point distances along the X-plane, Y-plane, and Z-plane, in both metric and imperial units.

  8. Continue to measure further distances, or right-click, or press Esc, to exit.

The color of the measurement line is based on the Selections system color, part of the System Colors section on the Layers & Colors tab of the View Configuration panel ().

If you find an issue, select the text/image and pressCtrl + Enterto send us your feedback.
Feature Availability

The features available to you depend on which Altium solution you have – Altium Develop, an edition of Altium Agile (Agile Teams or Agile Enterprise), or Altium Designer (on active term).

If you don’t see a discussed feature in your software, contact Altium Sales to find out more.

Legacy Documentation

Altium Designer documentation is no longer versioned. If you need to access documentation for older versions of Altium Designer, visit the Legacy Documentation section of the Other Installers page.

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