Viewport Scale

Lock a viewport after its view and scale are correct. The lock prevents accidental zooming from changing the scale while you continue working on the Layout.

Changing a viewport scale should change the model view inside the sheet, not the physical sheet size. Keep the Layout and Page Setup unchanged, then modify only the selected viewport scale.

A viewport scale usually changes because the viewport is unlocked and somebody zooms inside it, or because a custom scale is being created accidentally. Restore the intended scale, reframe with PAN, and lock the viewport.

If the scale you need is missing from the viewport list, first select the viewport correctly, then use SCALELISTEDIT to inspect or add drawing scales. Do not use random zooming to imitate the missing scale.

Use SCALELISTEDIT when your office needs a legitimate scale that is not in the standard list. Add the scale once, name it clearly, then select it normally from the viewport scale list.

Resetting the AutoCAD scale list removes custom and unused scales and restores the drawing’s default list. Use it only after checking whether your project depends on office-specific or annotative scales.

The XP option of ZOOM sets model-space magnification relative to paper-space units. It is an older but useful method for controlled viewport scaling when you understand the required XP factor.

After setting a viewport scale, use PAN to move the model view into position. Do not use the mouse wheel to ‘center’ the view, because zooming can change the viewport scale.

One Layout can contain several viewports at different scales. Set each viewport independently, lock each one, and make sure annotations are designed to display correctly at those different scales.