How to measure a PDF on an iPad or iPhone

ScaleDraw runs in Safari, so an iPad or iPhone becomes a measuring tool for drawings on site, with no app to install.

1. Open ScaleDraw in Safari

   Go to scaledraw.app. To keep it handy, tap the Share button and choose Add to Home Screen.

2. Import the PDF

   Open the menu (the logo at the top left), then File → Import PDF…, and pick the drawing from Files, iCloud Drive or a download.

3. Calibrate

   Tap Calibrate, drag along a known dimension with your finger or Apple Pencil, and type its length. If the PDF was drawn at a stated scale such as 1:50, you can type that ratio instead.

4. Measure

   Pick Measure and drag between points. Pinch to zoom in on the ends for accuracy.

5. Save the result

   Export a JPEG from the menu and tap Save to put it in Photos or Files, or send it straight from the share sheet.

Tips for touch screens

• Zoom right in before placing the ends of a line: a fingertip covers a lot of drawing.
• An Apple Pencil gives the most precise lines.
• On iPhone, the less common tools are under More in the toolbar.