Measure items in PDFs using Acrobat Reader and Preview

Accurate measurement is crucial to the creation of quality music notation. Music engraving rules have tightly interdependent relationships, and even a small difference in those values can have a large impact on the clarity of the notation.

The foundational unit of measurement in music notation is the space — the distance between two staff lines. As important as this unit is — and you can read all about it elsewhere on Scoring Notes — the space is, ultimately, a unit of relative measurement.

When the final output is achieved, however, everything on the page will be measured in absolute terms such as inches, millimeters, and points. Tell your print shop that your page is 150 spaces wide, and you’ll be met with a blank stare.

So when it comes to creating legible music, it’s important to come to grips with those measurements, as well. The size of a staff and page determines the overall layout of the music and whether or not it’s readable in conventional settings. (Yes, there’s a Scoring Notes article for that, too.)

All of the major scoring programs have a bazillion settings to control measurement of all sorts of notational items. In this article, though, we’ll talk about taking measurements from something that’s already been created in the form of a PDF.

There are good reasons you might want to know the measurements of items in a PDF. You might have a task where you need to closely match the look of an existing edition, either to make an insert or to replicate its style more broadly. Another scenario would be if you’re scaling music up or down for printing, and want to make sure that your results match your desired specs.

Whatever the case, there are two good, free, and widely available options at your disposal: Adobe’s Acrobat Reader and Apple’s Preview. Acrobat is the more robust of the too, plus it’s cross-platform, so we’ll start there.

Measure PDFs using Acrobat Reader

If you haven’t already downloaded and installed Acrobat Reader on your computer, be sure to that first.

Open up the PDF you wish to measure, and choose Tools > Measure.

In the secondary toolbar, click the Measuring Tool. You’ll notice the Measuring toolbar and the Measurement Info floating windows appear (they may be located in different areas of your screen).

The settings displayed above are generally the ones you’ll want use. From left to right, the Snap Types are:

• To snap the measurement to the end of a line, select Snap To Paths .
• To snap the measurement to the endpoint of a line, select Snap To Endpoints .
• To snap the measurement to the midpoint of a line, select Snap To Midpoints .
• To snap the measurement to the intersection of multiple lines, select Snap To Intersections 

You’ll generally want to keep all four of those selected. For instance, if you want to measure the distance of a staff from top to bottom, you’ll want Acrobat’s help in snapping the measurement to the line (Snap to Paths), keeping in mind that distance is measured from the midpoint of the staff line (Snap to Midpoints).

The Measurement Types are Distance, Perimeter, and Area. Most of the time you’ll be measuring distance.

Before you start measuring, you may wish to head over to Preferences > Units and set Page Units to your desired unit of measurement. Here, I’ll set it to Millimeters so that I can get an accurate measurement of the size of a staff.

Measuring something is as easy as clicking at one endpoint, dragging to the other endpoint, and double-clicking. Be sure to hold down the Shift key to constrain your measurement to increments of 45 degrees to insure an accurate reading.

What’s nice is that you can change the settings in Preferences > Units to different units, and the measurements you’ve already taken will remain unchanged. For instance, I might want to measure the staff size in millimeters, but I would want to take the page margin in inches, and the text size in points.

Acrobat lets me do all three:

If you want to get really fancy, there are even more tools available if you right-click the document while using the Measuring tool:

For example, you could export your measurements to a spreadsheet and instantly create a style guide:

That’s not all. You can save these annotations in your document, which is very helpful if you need to refer to them later or send them to a collaborator to quickly visually convey the specifications of your document.

Measure PDFs using Apple Preview

The built-in tool in Preview isn’t quite as elaborate as Acrobat, but it’s helpful in a pinch if you’re already working in Preview.

Open your document in Preview, and select the Selection tool from the toolbar.

Then, simply make a selection using the mouse. You’ll want to zoom in at a sufficiently high level to get the most accurate reading possible.

Choose Tools > Show Inspector, or use the keystroke Command-I, and head over to the fourth tab with the ruler icon. Choose your desired unit of measurement. Millimeters aren’t an option, so choose Centimeters instead and use your basic math skills to move that decimal over one point.

Here, you can see the height of the staff is 0.76 cm, or 7.6 mm:

As they say, measure twice, cut once — or now, you can measure your measure over and over again, and set the bar even higher for your musical notation creations.