Measure Distances, Angles and Areas in an Image
Click points on your image to measure distances, paths, angles, rectangles, circles and areas. Results appear in pixels; to get cm, mm or inches, draw a line over something with a known size — or enter the real width or height of the whole image, for example its print size. Your photo stays on your device: everything runs in the browser.
Allowed Filetypes: JPEG, JPG, PNG, WebP, AVIF, BMP, GIF
How to measure in an image online
- 1Add an image: click the upload area, drag a file in, or paste it from the clipboard
- 2Pick a tool: Distance, Path, Angle, Rectangle, Circle or Area
- 3Click points on the image — lengths, angles and areas appear immediately, in pixels
- 4For real units, calibrate once: draw a line over something with a known size and enter its length, or set the real width or height of the whole image
- 5Drag any point to fine-tune, then copy the values or download the annotated image
Frequently Asked Questions
How do I measure a distance in an image?
Choose the Distance tool and click two points. The length between them appears right away, in pixels by default. Drag either endpoint to adjust it, and zoom in or use the magnifier to hit the exact pixel.
How do I measure in cm, mm or inches instead of pixels?
A photo doesn’t know real-world sizes, so you set the scale once — in one of two ways. Either draw a calibration line over something in the picture whose size you know: a ruler, a credit card (8.56 cm wide), a door, the scale bar on a floor plan. Or, if you know the real size of the whole image — for example the size it will be printed at — enter its width or height directly. Every measurement is then converted to mm, cm, m, inches or feet.
How accurate are the measurements?
Pixel measurements are exact. Real-world results are as good as your calibration: they are reliable for flat, front-facing subjects such as scanned documents, floor plans, screenshots and product photos. If the photo was taken at an angle, or objects sit at different distances from the camera, a single scale cannot hold across the whole picture — place the reference next to, and in the same plane as, the thing you measure.
What can I measure besides straight distances?
Paths (total length along several points), angles in degrees (three clicks — the second one is the corner), rectangles (width, height, diagonal and area), circles (radius, diameter, circumference and area) and free-form areas (area and perimeter). You can also load several images at once; each keeps its own measurements and calibration.
Can I measure how big something will be when printed?
Yes. Click “Set image size” and enter the width or height the image will be printed at. All measurements then show the size things will have on paper — handy for checking layouts, sewing patterns or plans before printing.
Are my photos uploaded anywhere?
No. The image, your points and all calculations stay in your browser — nothing is sent to a server.
I have another question
We are always happy to get feedback to expand the tool or clarify things.