Measure Gravel Area from a Plan

Calibrate a top-down plan and trace the area that needs gravel.

A uniformly scaled top-down plan is required. Perspective photographs need rectification and can give misleading measurements. This tool estimates horizontal area, never depth.

Your plan stays on your device.

Choose an image, calibrate a known length, then trace your area.

Calibrate and trace to measure

Select two reference points, then enter their known real length.

How do you measure area from a drawing?

Mark two endpoints of a known length, enter that length, then trace the boundary. Scale is real length divided by reference length in image pixels. Polygon area in pixels squared multiplied by scale squared gives square meters.

Calibration example

If a 10 m reference spans 500 image pixels, scale is 0.02 m/pixel. A traced 200 × 100 pixel rectangle represents 20,000 × 0.02² = 8 m². Use a long, clearly visible reference and check a second distance to catch distortion.

What happens to my image?

PNG, JPEG and WebP images up to 15 MB stay in this browser’s memory. They are not uploaded or saved in project JSON. Removing the image or closing the page discards it. PDF import and perspective correction are not included; export a flat plan as an image first.

Ordinary perspective photographs are unreliable without rectification. Trace a top-down, uniformly scaled plan, and verify critical measurements on site. Read our measurement limitations.