Guide

How to set the scale on a construction PDF.

Every measurement depends on the scale being right, and the scale note is not always right. Here is how to set it, and how to check it before you measure anything.

Redpen showing the result of Autoscale on a floor plan: 1/4 inch = 1 foot, from 7 dimensions

Steps

Four steps.

1
Check the note against a written dimension
Pick a dimension printed on the sheet and compare it to what the scale note would give. A sheet that was resized or plotted at half size will not match.
2
Choose how to set it
Pick a preset (architectural, engineering or metric) when the note is right. Calibrate by clicking two points and typing the real distance when you know one length. Run Autoscale to read the printed dimensions and find the scale for you.
3
Apply it to the page or the whole set
Apply the scale to this page, a range or every page. Sheets with details drawn at a different scale can have their own scale for just that area.
4
Test it on a length you know
Measure something with a written dimension. If the number matches, you are ready to measure.

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Resized sheets break the note

A sheet printed to PDF at a different size keeps its old scale note. Trust the dimensions, not the title block.

Details can have their own scale

A 3/4 inch detail on a 1/8 inch plan needs its own scale, or every measurement in it will be wrong.

Verify before a bid

Autoscale shows how many dimensions agree and how far off each one is. Look at that before you rely on it.

Questions

Short answers.

How do I know the scale on a PDF is wrong?

Measure something with a written dimension. If your measurement differs from the number on the drawing, the scale is off. Sheets that were resized, reduced or fit to page are the usual cause.

What is Autoscale?

Autoscale reads the dimensions printed on a sheet and works out the true scale from them, instead of trusting the scale note. It reports how many dimensions agree.

Can one sheet have two scales?

Yes. Draw a region around a detail and give it its own scale, so measurements inside it use that scale.

Can I set the scale on every page at once?

Yes. Choose to apply the scale to a range of pages or the whole document.

Screenshots use a sample plan, not a real project.

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