Find a known dimension on the PDF
Start with a dimension actually printed on the sheet. The sample cabinet elevation has a base run marked 12'-0". That is the calibration reference; the apparent size of a cabinet or a screen ruler is not.
Turn on Snap in the status bar so the endpoints are easier to select. When calibrating a shop drawing from a known dimension, choose the reference line endpoints rather than the edges of the dimension text. Zoom in enough to see what you are selecting.
Calibrate a PDF in feet and inches
The video begins with Not calibrated in the bottom-right corner. Click it to open Calibrate. The button beside PDF Distance lets you measure the reference directly on the PDF. Drag between the endpoints of the printed 12-foot dimension; the measured PDF distance fills in when you return to the dialog.
In this example the page distance reads 432 points. Enter 144 as the real distance because 12 feet equals 144 inches, then select Feet + Inches and click OK. This establishes the relationship between page distance and real length. It does not change the size of the drawing itself.
Open Calibrate
Click Not calibrated in the status bar.
Measure the printed reference
Use the button beside PDF Distance and drag across the known dimension.
Enter the real length
For this 12-foot reference, enter 144 inches and select Feet + Inches.
Apply the scale
Click OK before taking a new measurement.
Measure a cabinet opening on the PDF
Choose Measure or press M, then drag from one side of the opening to the other. The tutorial's fridge opening reads 3 feet. This shows a calibrated distance measurement on a kitchen elevation, not an automatic takeoff or a fabrication check.
Use the same approach to measure between clearly defined points on a cabinet shop drawing. The displayed result depends on the source drawing, its calibration and the points you select. Changing the screen zoom helps you select a point; zoom alone does not set the PDF scale.
Once the scale is calibrated and checked against another known dimension, you can also measure an opening without its own printed dimension. Treat that reading as a drawing reference and confirm it before fabrication.
Check the PDF scale with a second dimension
Measure a different dimension whose value is already known. The sample pantry is marked 2 feet and the measurement reads 2 feet. This second check is useful because simply measuring the same calibration line again will not expose every setup mistake.
If a known dimension does not match, check the units, reference endpoints and drawing revision before continuing. A scanned or stretched sheet, an enlarged detail or a different page scale may need its own check. Confirm critical site and fabrication dimensions independently; a measurement from a PDF is a drawing reference.
Common questions
What do I enter for a 12-foot calibration in Feet + Inches?
In the demonstrated Calibrate dialog, enter 144 for the real length and select Feet + Inches. Twelve feet equals 144 inches. Use the value printed on your own drawing, not the tutorial's sample value.
Why does the PDF distance say 432 instead of 12?
PDF Distance is the distance on the page. The real length field describes what that page distance represents. In the sample, 432 PDF points represent a 12-foot run; entering the real length establishes the scale.
Can I calibrate a drawing with no known dimension?
You need a reliable reference. Do not assume the width of a door or cabinet to establish scale. Obtain a dimensioned drawing or another verified reference before relying on measured values.
Is the M shortcut the measuring tool?
Yes. This tutorial uses M to select Measure in LayrPDF. Calibration is a separate step and must be checked before relying on the result.
Video transcript
Read the transcript
0:00Here's how to set the scale, and measure this opening, in LayrPDF.
0:04First, find a dimension that's already printed on the drawing.
0:08This base run says twelve feet, so we'll use that one.
0:15Turn on Snap, down in the status bar. It grabs the ends of lines,
0:18so your clicks land right on the marks.
0:22Now click Not calibrated, bottom right.
0:25That opens the Calibrate window.
0:27See the three dots next to PDF Distance?
0:29Click them to measure right on the drawing.
0:33Drag from one end of the twelve foot dimension to the other.
0:39Snap locks on, and the PDF distance fills in.
0:42Now the real length. With feet and inches, you type it in inches.
0:47So twelve feet is a hundred forty-four.
0:50Then set the units to Feet plus Inches.
0:54Click OK, and the sheet's calibrated.
0:57Now grab the Measure tool. Or just press M.
1:01Drag across the opening, side to side.
1:06And there it is. Three feet.
1:10Before you trust it, check one more you know. The pantry's marked two feet.
1:17And it measures two feet. The scale's good.
1:21So: find a known dimension, calibrate from it, measure, and check one more.
1:26See LayrPDF. The link's in the description.
Put it into practice
Try these steps on your next drawing.
Open a PDF in LayrPDF and follow along with the lesson.
