Image Measurement Tool
| Line | Start (x, y) | End (x, y) | Length | Action |
|---|---|---|---|---|
| Total: | 0 | |||
Image Measurement
Make approximate measurements in an image, using an object with known size for scale. Online, without upload, simple and free. For the best accuracy, the objects should be close to each other — unlike in the sample image below.
Image Measurement, or Photogrammetry, is a technique used to obtain accurate measurements from photographs. By analyzing the scale of a reference object in an image, you can determine distances, lengths, angles, and areas of other elements in the same photo.
📐 How to Measurement Something in a Image
Who is this tool for? Architects, designers, engineers, DIYers, or anyone who needs to measurement objects using a image.
🛠️ Steps:
- Upload Image: Use the “Upload Image” button.
- Set Reference: Draw a line over a known object and enter its actual size in the "Reference Length" field. Choose unit (px, cm, in).
- Measurement: Draw another line to measurement new distances. Tool shows actual length.
- Download/Share: Export results or share directly via the buttons provided.
📏 Tips for Accuracy:
- Use a known object (e.g., ruler, A4 paper) as a reference.
- Ensure the image is flat (no distortion or angled shots).
- Use the longest possible reference line for more precision.
How to measurement something in a image
It's simple to determine distances on maps or technical drawings such as architectural (floor) plans when you have its scale and a ruler.
Because everything is in a single plane, measurements can be taken directly. The real-world dimensions are then obtained by simply applying the scale.
Photos on the other hand are a two-dimensional projection (image) of the three-dimensional world (object).
As a result, objects appear smaller with increasing distance — that's called perspective.
Without additional information, it cannot be determined whether it is a small object nearby or a large one far away (depth perception is more difficult with one eye closed).
Consequently, to determine the size of an object from a single image, a reference object for scale needs to be in the same image plane, i.e. close-by and at the same distance from the camera.
Additionally, camera lenses cause distortions (think fish-eye view). As a result, expect this method to be useful only for estimates. The accuracy depends very much on the image.