How-to guide · how to scale an entire drawing in autocad

How to scale an entire drawing in AutoCAD

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By Sumana Kumar · Published 9 Jul 2022 · Updated 4 Mar 2025

Scaling an entire drawing is a routine but high-stakes operation. You do it when a file came in at the wrong size — a PDF traced at no particular scale, a drawing in the wrong units, or a sketch that needs resizing to a real dimension. Get it right and the whole drawing snaps to its true size; get it wrong and every dimension on the sheet is now lying. The SCALE command does the work, and its Reference option is the precision tool that makes scaling-to-a-known-length foolproof.

This guide covers scaling everything by a known factor, scaling by reference to a real-world dimension, and choosing a base point that keeps the drawing where you want it. We will also flag the things that bite people — text and dimensions scaling with the geometry, annotation that should not move, and the difference between scaling the model and scaling a viewport. The same techniques apply to a single imported symbol that arrived oversized as much as to a full plan.

Step 1 — Select everything to scale

Decide first whether you really want everything. To scale the whole drawing, type SCALE (or SC), then select all objects — type ALL and press Enter, or window the entire drawing — and press Enter to finish selecting. Make sure nothing important is on a frozen or locked layer that the selection will miss; thaw and unlock first if so, or the drawing will scale unevenly.

If you only want to resize part of the drawing, select just those objects instead. But for a true whole-drawing rescale, ALL is the reliable choice, since it catches every object regardless of where it sits on the canvas.

Step 2 — Pick a base point

After selecting, SCALE asks for a base point. This is the fixed point the scaling pivots around — it stays put while everything else grows or shrinks toward or away from it. For a whole-drawing rescale, a sensible base point is the drawing origin (type 0,0 and Enter) or a known corner, so the geometry stays in a predictable place afterward.

If you pick an arbitrary point in empty space, the drawing will scale but may shift far from where you expect. Snapping the base point to a meaningful reference — an origin, a grid corner, a datum — keeps the rescaled drawing positioned sensibly and easy to find.

Step 3 — Enter a scale factor

With the base point set, SCALE asks for a scale factor. A factor greater than 1 enlarges (2 doubles the size), a factor between 0 and 1 shrinks (0.5 halves it). If a drawing came in at half its true size, scale by 2; if it is ten times too big, scale by 0.1.

This direct-factor route is perfect when you know the ratio. A common case is a units fix: a drawing built in metres opened in a millimetre template appears 1000 times too small, so scaling by 1000 corrects it. When you do not know the factor but do know a real dimension, use the Reference option instead — covered next.

Step 4 — Use the Reference option for known dimensions

The Reference option is the precise way to scale a drawing to a real measurement, and it is the one to learn well. After picking the base point, type R and press Enter for Reference. AutoCAD asks for a reference length: snap to two points across an object whose true length you know — say, a door you know should be 900 mm, or a scale bar. Then it asks for the new length: type the correct real value (900) and press Enter.

AutoCAD calculates the exact scale factor needed to turn that reference distance into the real one and applies it to the whole selection. This is invaluable for traced PDFs and scanned drawings that have no defined scale: pick any feature of known size, tell AutoCAD what it should measure, and the entire drawing snaps to true size without you doing any arithmetic.

Watch out for text, dimensions and annotation

Scaling everything scales the text and dimension geometry too, which is usually fine when you want the drawing physically larger, but a problem when you only meant to resize the geometry and keep annotation at its set height. Annotative objects behave differently again, adjusting to annotation scale rather than the SCALE factor. Decide upfront whether annotation should ride along.

Dimensions are the sharpest hazard: after rescaling, confirm that dimension values now read correctly. If your dimensions are associative and measuring the geometry, they update to the new real size automatically — exactly what you want when fixing a wrong-scale file. If any dimension text was overridden manually, it will not update and will now be wrong, so check those by hand.

Scaling model geometry versus a viewport

A frequent confusion: scaling the drawing in model space versus setting a viewport scale in a layout. SCALE physically resizes the geometry. A viewport scale, set in paper space, changes how the model is displayed on a sheet without altering the model at all. If your goal is to plot at 1:50, you set the viewport scale — you do not resize the model with SCALE.

Use SCALE when the geometry itself is the wrong size and must be corrected, such as a wrong-units import. Use viewport scale when the model is correct and you are arranging how it prints. Mixing these up — rescaling correct geometry to 'fit' a plot scale — corrupts the drawing's real dimensions, so be clear which problem you are solving before you reach for SCALE.

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Questions

Frequently asked

How do I scale a whole drawing in AutoCAD?+

Type SCALE, select all objects (type ALL and Enter), press Enter, pick a base point such as 0,0, then enter a scale factor. A factor above 1 enlarges, below 1 shrinks. For a known target dimension, use the Reference option instead of a numeric factor.

How do I scale a drawing to a known dimension?+

Use the Reference option. Start SCALE, select the objects, pick a base point, type R for Reference, snap across an object whose true length you know to set the reference length, then type the correct real length. AutoCAD computes the exact factor and applies it.

My imported drawing is 1000 times too small. What scale factor do I use?+

Scale by 1000. This is the classic metres-in-a-millimetre-template situation: geometry drawn in metres appears 1000 times too small in a millimetre drawing. Selecting all and scaling by 1000 (around a sensible base point) corrects it.

Should I scale the model or set a viewport scale to plot at 1:50?+

Set a viewport scale in the layout. SCALE physically resizes geometry and would corrupt your real dimensions. Viewport scale changes only how the correct model displays on the sheet. Use SCALE only when the geometry itself is the wrong size.

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