ImageScale
Calibrated measurement tool for images and microscopy
Source
Scale
Measure
Display
1. Upload an image. 2. Click Calibrate, drag the amber line onto a known distance (or use Detect scale bar and click on an existing bar), enter its length → the scale is set and the calibration line disappears.
3. Turn on Ruler, Coord. system, circles or polygon as needed — everything is hidden by default to keep the canvas clean.
Drag a circle or polygon by its center handle to reposition it after measuring; value labels can be dragged too. Set line color and width under Display.
How it measures
Open a JPEG or PNG and calibrate it once on something of known length in the picture: drag the calibration line onto it, or let Detect scale bar find a microscope's scale bar, and enter the length in µm, mm, cm, m or km. From then on the ruler, the coordinate system, the circles and the polygon measure in that unit: distances and angles, diameters of circles through three points, and the perimeter and area of a polygon.
Your image stays with you
The image is opened in your browser. It is not uploaded anywhere, and nothing is stored.