The short answer
Why use Measure Distance?
Measuring by eye is guesswork. Placing points on the image gives an exact number, and a scale turns pixels into real units.
Two red points appear on the image. Drag them onto the two ends of what you want to measure, or type the start and end X and Y in pixels. The status line shows the straight-line distance, and the downloaded image has the line and both points drawn on it.
With Pixels per unit at 1 the answer is in pixels. For centimeters, measure something of known length in the same photo first. If an 8.56 cm bank card spans 342 pixels, Pixels per unit is 342 ÷ 8.56 ≈ 40, and every distance after that reads in centimeters.
That scale is only right for things in the same flat plane as the reference and the same distance from the camera. A photo taken at an angle stretches one direction more than the other, so flatten a plan or document with Perspective Crop before you measure it.
Where Measure Distance fits
Floor plans
Read a wall length from a scanned plan that has a scale bar.
Design checks
Measure the gap between two elements in a UI screenshot, in pixels.
Object sizes
Estimate the size of an item photographed next to a ruler or a card.
Start to finish
How to use Measure Distance
- 01Tap Choose image and pick the photo, screenshot, or plan.
- 02Drag the two points onto the start and end of what you want to measure. You can also type exact X and Y values below the preview.
- 03To get real units, set Pixels per unit from something of known length in the photo. The result then shows as units, meaning whatever unit you measured that object in.
What to expect from Measure Distance
| Check | What it means here |
|---|---|
| Supported input | JPEG, PNG, WebP, GIF, BMP, SVG and browser-supported AVIF images |
| Main controls | Draggable points, exact X and Y fields, and an optional pixels-per-unit scale |
| Output | The measurement on screen and a marked-up copy of the image |
| Working limit | 50 MB and 50 megapixels per image |
Measure Distance tips
- Leave Pixels per unit at 1 to read the distance in plain pixels.
- A bank card is 8.56 cm wide, a handy reference for setting the scale.
- Type exact start and end X and Y when dragging on a phone is too rough.
- Flatten angled shots with Perspective Crop first, or the scale is off in one direction.
Measure Distance FAQ
Something missing? Ask us.
How do I measure in cm instead of pixels?
Does Measure Distance upload my file?
Is Measure Distance free to use?
Why did Measure Distance fail or look wrong?
Related tools
More in Measurement.