Measure distances, angles, areas and diameters in any image. Set a real-world scale and get precise measurements instantly — no upload, no install, no account.
① SCALE
Draw a line over an object with a known size. Enter its real-world value and unit — mm, cm, inches, anything.
📄 PDF SUPPORT
Load multiple images or PDF files at once. For multi-page PDFs, load a single page, a custom range (e.g. 1, 3, 5–8), or all pages at once. Each page gets its own scale and measurements in the filmstrip navigator.
↔ DISTANCE
Click two points to measure the distance between them. Drag endpoints to adjust. Results shown in your chosen unit.
⌀ DIAMETER
Click the center point, then an edge point. The full circle is drawn automatically. Drag the center or edge points to adjust.
∠ ANGLE
Click three points — first arm, vertex, second arm. The angle is calculated with a live arc preview as you draw. No scale required.
⬡ AREA
Click to place polygon vertices. Choose straight or bezier segments. Close by clicking the first point or Enter. Area in real-world units².
⬠ PATH
Trace any outline with straight or bezier segments. Close for a perimeter or Esc to keep as an open path. Length calculated in real-world units.
✎ NOTE
Click anywhere on the image to add a free text label. Notes appear as yellow pins with a tooltip and are included in PNG and PDF exports.
∡ PROTRACTOR
Measure the angle between two independent lines. Click 4 points — two per line. The angle at their intersection is calculated with an arc indicator. No shared vertex needed.
⊥ POINT TO LINE
Measure the perpendicular distance from a point to a reference line. Draw the reference line with two clicks, then click the point. A right-angle marker shows the foot of the perpendicular.
⌒ ARC LENGTH
Measure the length of a circular arc. Click the center, then two points on the arc. The arc is drawn and its length calculated in real-world units.
⊙ POINT COORDINATES
Set a coordinate origin (0,0) then place measurement points. Each point shows its X and Y coordinates relative to the origin. Origin and points can be dragged to update coordinates dynamically.
↺ ROTATE
Rotate the image 90° left or right before measuring. Useful for portrait photos or images taken in landscape orientation.
⬜ PERSPECTIVE CORRECTION
Correct perspective distortion by clicking the 4 corners of a known rectangle. The image is warped flat for accurate measurements.
⊕ ZOOM & PAN
Scroll to zoom in on fine details. Hold Space and drag to pan. The precision cursor magnifier helps you pick exact pixels.
Architecture & engineering
Measure floor plans, blueprints and technical drawings — load PDF files directly or images. Correct perspective from oblique shots before measuring.
Science & research
Measure specimens in microscopy images, cell areas, structural angles in research photos. Export annotated images and CSV data for reports.
Product design
Document prototype dimensions, surface areas and component angles from reference photos. Add notes directly on the image.
Construction & real estate
Measure wall lengths, room areas and lot perimeters from site photos and listing plans. Export a PDF report with measurements.
Quality control & inspection
Measure part dimensions, defect areas and assembly angles from inspection photographs. Annotate with notes and export as a PDF report.
Medical & dental imaging
Measure structures in X-rays, radiographs and clinical photos. Works with any image format, fully offline — no upload to any server.
Maps & satellite imagery
Estimate distances and land areas from satellite views or printed maps with a known scale. Polygon area tools handle irregular parcels.
Forensics & accident reconstruction
Reconstruct scenes from photos, measure distances and angles, add labelled notes. Runs offline with no data leaving the device.
Can I measure distances in a PDF file?
Yes. Mesuro supports PDF files directly — drag and drop a PDF or use the Load button. For multi-page PDFs, a page selector lets you choose which page to open, load a custom range (e.g. 1, 3, 5–8), or load all pages at once. Each page is rendered at high resolution so measurements remain precise.
Can I load multiple images at once?
Yes. Use the Load button or drag and drop multiple image files onto the canvas. Each image becomes a separate page in the filmstrip at the bottom. Click any thumbnail to switch between pages — scale calibrations and measurements are saved independently per page.
Can I load all pages of a PDF at once?
Yes. When you open a multi-page PDF, the page picker lets you load the current page, a custom range (e.g. 1, 3, 5–8), or all pages at once. Each page becomes an independent entry in the filmstrip with its own scale and measurements.
How does multi-page export work?
CSV export combines all pages into one file with page and source columns identifying each measurement's origin. PDF report export creates one section per page — each section contains the annotated image and its measurement table, all in a single downloadable PDF.
How do I measure a distance in an image online?
Set a scale by drawing a line over an object with a known size, then use the Distance tool to click two points. Mesuro converts the pixel distance into real-world units automatically.
Is my image uploaded to a server?
No. Mesuro runs entirely in your browser. Your image never leaves your device — no upload, no storage, no account required. It works offline once the page is loaded.
Can I save my measurements and come back later?
Yes. Use the Save button (↓S) to export a .mesuro project file containing your image and all measurements. Load it again anytime to resume exactly where you left off.
What units can I use?
Any unit you want — mm, cm, m, inches, feet, or any custom label. You define the scale once and Mesuro applies it to all measurements automatically.
Can I export my annotated image?
Yes. Export as PNG, JPG or WebP at full original resolution with all annotations, or export a PDF report with the annotated image and measurement table, or export raw data as CSV.
What types of measurements does Mesuro support?
Distance (point-to-point, center-to-edge, point-to-line), angle (3-point or 4-point protractor), arc length, diameter (center+radius or 3-point circle), area (straight or bezier), path/perimeter, point coordinates, and text notes. Angles work without scale calibration.
How do I correct perspective distortion in a photo?
Use the Perspective Correction tool. Click the 4 corners of a known rectangle in the image (a door, tile, window, sheet of paper). Mesuro applies a homographic transform to flatten the perspective before you measure.
Can I add labels or text annotations to the image?
Yes. Use the Note tool (✎ N) to click anywhere on the image and type a label. Notes appear as yellow pins on the canvas and are included in PNG and PDF exports.
How do I measure an angle without knowing the scale?
The Angle tool works without scale calibration. Click the first arm point, then the vertex, then the second arm. The angle in degrees is displayed immediately.
Can I use Mesuro on mobile?
Yes. Mesuro has a mobile interface. Tap to load an image, use the toolbar to select tools. Long-press on the canvas to activate a precision zoom cursor for accurate point placement.
How accurate are the measurements?
Accuracy depends on your scale calibration and image resolution. The precision cursor magnifier zooms in 5× to help you place points on exact pixels. For best results, use the longest possible scale reference line.
What is the bezier curve mode for area and path?
Instead of straight polygon segments, bezier mode fits a smooth curve through your clicked points using a natural cubic spline. This gives smooth, professional-looking outlines for organic shapes. Control points can be dragged after creation to fine-tune the curve.
Can I measure the angle between two lines that don't share a vertex?
Yes. Use the 4-point protractor mode under the Angle tool. Click two points on the first line, then two points on the second line. Mesuro computes the angle at their intersection even if the lines don't physically cross in the image.
How do I measure coordinates in an image?
Use the Point Coordinates tool. First click sets the origin (0,0). Then place measurement points — each shows its X and Y position relative to the origin in real-world units. Drag the origin or any point to update all coordinates dynamically.
Does Mesuro detect edges automatically?
Yes. Enable Edge detect in the View panel. When active, measurement points snap to the nearest detected edge using a Canny edge detection algorithm. A snap indicator shows when edge snapping is active. This greatly improves precision on sharp-edged objects.
Can I move measurement labels after placing them?
Yes. In idle mode (no tool selected), hover over any measurement label — the cursor changes to a grab hand. Drag the label to reposition it. A leader line connects it back to the measurement. All measurement points can also be dragged to adjust the measurement itself.
Mesuro — measure twice. in pixels. — free online image measurement tool