How to Measure Square Footage from a Floor Plan

You have a floor plan. You need square footage. Here's how to get it with Area Sketcher in five steps.

1. Upload your floor plan

Drop a JPG, PNG, or PDF into Area Sketcher. Higher resolution = better accuracy. Make sure the full area you want to measure is visible and the image isn't rotated.

2. Set the scale

Click Set Scale and draw a line along a known dimension, a labeled wall length, a door width (typically 3 ft), or a scale bar. Enter the real-world measurement. This tells the tool how to convert pixels to feet or meters.

Zoom in when tracing the reference line. Scale accuracy determines everything downstream.

3. Draw areas

Pick a tool:

Polygon: click to place points around irregular shapes. Click the first point to close.
Rectangle: click and drag for standard rooms.

Each closed shape shows its area immediately. Use Backspace to undo the last point, Escape to cancel.

4. Organize

Name each measurement and group them into categories (e.g. "Main Floor", "Basement"). Each category shows a subtotal. The sidebar shows a running total.

5. Save

Projects auto-save to local storage. For a permanent backup, click Download to export a JSON file with the image, measurements, categories, and scale. Re-upload it anytime.

Common mistakes

No scale set: measurements stay in pixels
Low-res image: hard to trace edges accurately
Not zooming in: small placement errors compound over large areas