How to Change Units in SolidWorks (Step-by-Step Guide)

Change units on the document you have open, set them by default with a template, and keep one unit standard across the whole team.

You can switch a SolidWorks document from millimeters to inches in about four clicks, and set every new file your team creates to open in the right system by default. This guide covers both, plus the part most tutorials skip: keeping one unit system across a team so a metric model and an imperial drawing never reach manufacturing together.

Sibe is a collaboration-first CAD Document Management platform with a native add-in for SOLIDWORKS® 3D CAD. Templates, custom properties and the files built from them sit in one versioned workspace, so the unit standard you set once is the one your whole team opens tomorrow — and every revision that follows is tracked as engineers check work in.

Change units for the document you have open

The quickest route is the status bar, bottom right of the SolidWorks window:

1. Open the part, assembly or drawing
2. Click the unit system shown in the bottom-right corner (it reads MMGS, IPS or similar)
3. Pick the system you want from the list
4. Carry on modeling — dimensions redisplay immediately

The systems on that list:

• MMGS — millimeter, gram, second. The default for most metric mechanical work
• IPS — inch, pound, second. Standard for US manufacturing drawings
• CGS — centimeter, gram, second
• MKS — meter, kilogram, second. Usually seen in simulation and large-structure work
• Custom — define length, mass, angle and decimal places yourself

This change affects only the active document. Close it, open another, and you are back to whatever that file was saved with.

Set the units properly, with decimals and dual dimensions

The status-bar shortcut only swaps the system. For control over precision, go to Tools > Options > Document Properties > Units. There you set:

• Length unit and the number of decimal places, separately for length and for dual dimensions
• Angle unit — degrees, degrees/minutes, or radians
• Mass and volume units, which drive what mass properties reports
• Fractions rather than decimals, for imperial drawings that call for them
• Dual dimensions, so a drawing shows millimeters with inches in brackets

Decimal places matter more than the unit system on a released drawing. Two decimal places on a millimeter dimension implies ±0.01 mm to a machinist reading it as a tolerance convention. Set precision to what you can actually hold, not to what looks tidy.

Make it the default for every new file

Changing units on every new part gets old fast. Bake it into your templates instead:

1. Open a new part, assembly or drawing and set units the way you want them under Document Properties
2. Set the rest of the document properties at the same time — drafting standard, dimension font, grid, material
3. Go to File > Save As and choose Part Template (*.prtdot), Assembly Template (*.asmdot) or Drawing Template (*.drwdot)
4. Save it into your templates folder
5. Confirm the folder is listed under Tools > Options > System Options > File Locations > Document Templates

Every file created from that template opens with your units already set. Do this once for each of the three document types — a part template alone does not cover the drawings.

What changing units does not do

This trips people up, so it is worth stating plainly. Changing the unit system changes how dimensions are displayed. It does not rescale the model. A 100 mm shaft switched to IPS becomes a 3.937 in shaft — same physical part, different number on screen.

If you actually need to rescale geometry, that is Insert > Features > Scale, and it is a different operation with different consequences for your feature tree. Do not reach for units when you meant scale.

Drawing units are their own setting

A drawing document carries its own unit setting, independent of the model it references. Change the part to IPS and the drawing keeps whatever it was saved with. That mismatch is exactly how a metric model ends up on an imperial title block, so check both before a release.

Four things to check on any drawing you are about to send out:

• The unit note in or near the title block, and whether it matches the dimensions
• Dual dimension settings, if the reader works in a different system to you
• Precision on critical features, which drives how the part is inspected
• Mass properties, which report in the document's mass unit, not the model's

Check units before anything leaves the building

Neutral formats carry units, but they carry the units the file was exported with. A STEP or IGES export made from a document set to centimeters lands in someone else's session at a hundredth of the size you meant. Before you export or share:

• Open the document properties and confirm the unit system, not just the status bar
• Check one known dimension in the export against the model
• State the units in the file name or the covering message when sending outside your team
• Send the drawing alongside the 3D file, so the reader has the dimensions you intended

Keeping a whole team on one unit standard

Unit mistakes are almost never one engineer's error. They come from three templates in circulation, one of them from a laptop that was set up two years ago, and nobody knowing which is current.

The fix is boring and it works: one set of templates, one place they live, one version everyone pulls from. Add a custom property that records the unit system on the file itself, so the standard travels with the model rather than living in someone's memory. Then make sure the templates themselves are under version control — a template is a design decision, and it deserves the same history as a part.

Where Sibe fits

Sibe is a collaboration-first CAD Document Management platform with a native SolidWorks add-in. Your templates, parts, assemblies and drawings sit in one versioned workspace, so the team pulls the current template rather than a copy from a colleague's desktop. Engineers check files in and out directly in SolidWorks, and Sibe writes a new version on every check-in with the author, a timestamp and the change note.

Custom properties — unit system, material, article number, revision — travel with the file and are searchable from the add-in and the Web Dashboard, so you can find every document built on an old standard and fix it in one pass. When a unit mismatch does slip through, view and restore the previous version rather than rebuilding. Reviewers, clients and shop-floor teammates open a free public share link or scan a QR code and see the model in any browser — no Sibe account, no viewer install. More on version control for SolidWorks and CAD file management.

No servers, no VPNs, no admin hassles.

Book a free 20-minute demo or try Sibe free for 14 days — no credit card.