bScaler

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bScaler

A free tool for scaling, measuring & marking up PDF drawings from Bury Associates

A PDF drawing says “1:200 at A1”, but on screen that scale means nothing – the page isn’t printed at A1, so you can’t just measure it. bScaler lets you set the true scale, measure distances and areas, drop survey points, mark up the drawing, and export a marked-up PDF, a CSV of points or a DXF for CAD. It runs entirely in your browser – nothing you open is uploaded anywhere.

Install bScaler See what it does

What bScaler is for

You’re sent a PDF drawing and you just need a dimension, an area, or a few points off it. The title block says “1:200 at A1” – but on a screen that’s meaningless, because the PDF isn’t the full A1 sheet any more. Measuring it accurately usually means printing it out or opening specialist software.

bScaler fixes that in the browser. Tell it the true scale (from the sheet size and ratio, or from a scale bar on the drawing), and then measure straight off the PDF – distances, areas, coordinates and levels – and export a tidy marked-up copy to share. Your drawing never leaves your computer.

Installing bScaler

bScaler is on the Chrome Web Store, so it installs in a couple of clicks:

  1. Open the Chrome Web Store listing – Download & install bScaler from the Chrome Web Store.
  2. Click “Add to Chrome”, then confirm. The bScaler “b” icon appears in your toolbar.
  3. Click the icon to open bScaler in a new tab. Pin it from the puzzle-piece menu for one-click access.

The quick version – how to use it

  1. Open a PDF – click Open, or drag a PDF anywhere onto the window.
  2. Set the scale – click Scale. Either choose the sheet size and ratio (e.g. “1:200 at A1”) and let bScaler work out the true scale, or pick two points along a scale bar / known length and type the real length.
  3. Measure & mark up – use Distance, Area, Point and Mark-up. Snapping helps you land on the right spot on vector PDFs.
  4. Export – download a marked-up PDF, or export your points to CSV or the drawing to DXF for CAD.

Set the scale again for each new drawing (and each page) – different sheets have different scales.

Everything bScaler can do

The full toolset, grouped by what you’re trying to get done.

Scaling & measuring

📐Two ways to set scale

By sheet size & ratio (choose A0-A4 or custom and the ratio), or by a known length – pick two points on a scale bar and type the real distance. Use the scale-bar method if a drawing has been cropped or re-scaled.

📏Distance & area

Click along a line for a running distance, or round a shape for its area and perimeter. Every measurement is colour-coded and listed with totals, and you can drag any length, area or perimeter label clear of the drawing.

📍Survey points

Drop numbered points, each with a feature code, and read off coordinates (X, Y) or levels. Choose what every point shows on the drawing, then export them all to a CSV.

🌐Coordinate anchoring

Anchor a coordinate system or a level datum to the drawing, so points read as real eastings, northings and levels. Change it later and every point simply updates – nothing is lost.

🎯Smart snapping

Snap onto endpoints, mid-points, along a line, intersections, perpendiculars, centres and the nearest point – on the PDF’s own vector lines and on the mark-ups you add.

📐Ortho

Lock lines to right angles – square to the sheet, or square to two points you pick, for buildings that sit at an angle on the page.

✏️Mark up the drawing

Add multi-line text, lines, rectangles and circles in any colour (red by default) to annotate the drawing alongside your measurements.

⌨️Type exact sizes

While drawing, press D to type an exact distance – or a circle’s radius – instead of clicking it by eye.

Units, editing & exporting

🔢Metric or imperial

Switch between metres, millimetres and imperial (feet & inches) at any time – everything on screen updates instantly.

🎨Colour-coded, with totals

Every measurement has its own colour and appears in the side panel with running totals, so a set of areas or lengths stays easy to read.

🏷️Labels your way

Cycle what each measurement or point shows – lengths, totals, area and perimeter, coordinates, point numbers and codes – or switch individual labels on and off.

🔍Select & adjust

Select anything to move, resize or delete it, or open its properties to change colour and more. Drag a mid-point to add a corner to an area, reposition any label, and undo or redo as you go.

🔎Zoom & navigate

Scroll to zoom, drag a box to zoom to an area, or fit the whole sheet. Set a working area so Fit jumps straight to the part you’re on; hold Space to pan.

🗂️Layers

If a PDF has its own layers, a Layers tab lets you turn each one off and on, isolate one on its own, or click a line in the drawing to see – or switch off – its layer.

📄Export a marked-up PDF

Download a new PDF with your areas shaded and your lines, points and mark-ups drawn on top in their colours – labels and all – with a small bScaler credit and the scale in the corner.

📤Export to CSV & DXF

Export your survey points to a CSV (number, code, X, Y, level), or send the whole drawing to CAD as a DXF – the original linework plus your mark-ups, on tidy layers keeping colours and text sizes.

Handy shortcuts

Worth knowing:
  • Hold Space and drag to pan; scroll to zoom, or use Box to zoom to an area.
  • Double-click or Enter finishes a measurement; Esc cancels. Press D to type an exact length or radius.
  • Set the scale per page – reset it whenever you open a new drawing.

A couple of honest caveats

Accuracy depends on the scale you set and on the source drawing being a true, un-cropped copy of the stated sheet. Always verify anything critical against a reliable dimension. If a drawing has been cropped or re-scaled, use the scale-bar method rather than the sheet-size method.

Your measurements are saved into the exported PDF, not back into the original file, and nothing you open is uploaded anywhere – bScaler runs entirely on your own computer.

Who makes it

bScaler is built by Bury Associates, a surveying company that’s been producing land and measured building surveys since 1997. We built it because we needed it ourselves – and figured anyone who works from PDF drawings would too. It’s free.

Also worth a look: bCAD, our free tool for viewing and marking up DWG & DXF CAD drawings in the browser.