Analysis
Working prototype
Plan Scale Calibrator
Measure any scanned drawing — set one known length, read every other.
The problem
Students constantly get plans as scaleless images — a PDF screenshot, a scanned drawing, a photo of a board — with no way to pull real dimensions or areas off them. The usual fix is re-drawing in CAD just to measure one wall.
What this does
Drop in an image of a plan. Click two points along something you know the real length of (a door, a grid bay, a scale bar) and type that length — the tool calibrates. Then measure any distance, trace any area, and read real-world metres and square-metres directly off the drawing. Nothing is uploaded.
Try it
Loading tool…
What it does
- Load a scanned plan, screenshot, or photo.
- Calibrate: click two points across a known dimension and enter its real length.
- Measure: click points to read distances; trace a closed polygon to read its area — both in real units.
All in the browser; the image never leaves your device.
Why it's useful
- Pull dimensions and areas off any scaleless drawing in seconds.
- Check a precedent's room sizes, circulation widths, or site area without redrawing.
- Works on photos of physical boards and printouts, not just clean PDFs.
Honest limits
- Accuracy depends on your calibration click precision and how square/undistorted the scan is.
- A photo taken at an angle has perspective error — shoot square-on for best results.
- Single scale per image (assumes a uniform, non-distorted drawing).
Roadmap
Perspective-correction (deskew from four corners) and a draggable scale bar are the natural next steps.