AmpliaLine
Two clicks give you the straight-line distance between them. It is the tool the app hands you the moment calibration is finished.
Measure distance on a photoEvery Feature of the Amplia Image Measurement Tool
Measure distances, areas, angles and circles on any photo, plan or drawing. Calibrate once against something whose size you already know, then read real-world values straight off the image — and turn them into a PDF report, an annotated picture or a read-only link.
- Free to use — nothing to install
- No account needed to measure
- Five families of length units
Measurement tools
Six tools, and all of them are free.
Polyline
Click your way along a path and finish. You get the length of every segment, the total, and the angle at each bend — useful for a cable run, a baseboard, or a route that turns corners.
Polygon
Trace an outline and close it for the perimeter, the enclosed area, and the interior angle at every corner. Cross the contour over itself and it turns red and snaps the point back, rather than quietly handing you a wrong area.
Measure area on a photoCircle
Click the two ends of a diameter. Diameter, circumference and area all arrive at once, from the same two clicks — pipes, tanks, wheels, drill holes, tree trunks.
Angle
Click one arm, the corner, then the other arm. An angle does not depend on scale, so this is the one tool that works before you have calibrated anything.
Measure angles on a photoComments
Drop a numbered pin anywhere on the image and write a note against it. Pins get their own color, their own layer, and their own section in the PDF report. Any measured shape can carry a comment too, and picks up a small marker on its label when it does.
Click any measurement label and a details dialog opens with the same value converted across every family in the active system. Apart from the Angle tool, drawing waits until the image is calibrated — that is the next section.
PRO tools
Four more tools for the shapes the free set can only approximate.
CurvePRO
A smooth path fitted through the points you place, reporting total length, with a tension slider on each shape. Slide tension to zero and the curve becomes exactly the polyline through the same points — what is drawn is always what is measured.
Curve areaPRO
The closed version of the curve: a smooth region that reports both perimeter and area. This is the tool for a lake, a pond or any boundary that a straight-sided polygon rounds off at every corner.
EllipsePRO
Three clicks — the center, the end of one axis, then the second axis — give a rotatable ellipse with its area and circumference. The details dialog lists both full axes.
MagnifierPRO
Drag a rectangle around a crowded detail. It measures nothing; instead the region is rendered as an enlarged crop in the PDF report, so whoever reads it can see what the labels point at. Available inside a saved project.
Calibration and accuracy
One known dimension turns a picture into a scale drawing. Everything measured afterward inherits it.
One reference sets the scale for everything
Mark two points across something whose real size you already know — a door, a brick course, the scale bar printed on a plan — and type in the distance and its unit. The app switches straight to the Line tool, and every shape drawn from then on reads in real units.
Recalibrate any time — your shapes are kept
Picked the wrong reference, or found a better one? Editing the calibration value or unit re-scales every existing measurement in place. A full recalibration keeps every shape too: values show a dash until the two new points land, then everything recomputes. Worth knowing before you start: recalibrating clears the undo history.
Perspective calibration for angled photosPRO
Photograph a wall square-on and one scale fits the whole picture; photograph it at an angle and it does not. Perspective calibration describes a rectangle you know instead of a single distance — its width, height and unit, then its four corners in order — and maps every later measurement through that plane. Its limits, stated plainly: it lives inside a saved project, and Circle and Ellipse are unavailable while it is active.
Measuring from a photo is only trustworthy on one flat surface at a time, and no amount of software changes that. Each measurement page on this site sets out where photo measurement works well and where it quietly goes wrong.
Units and formatting
Five families of length units, three of area, and full control over how every number is printed.
| System | Families | Examples |
|---|---|---|
| Distance | Metric · Imperial · Nautical · Astronomical · Typography | mm, cm, m, km · in, ft, yd, mi · fathom, cable, nautical mile · AU, light-year, parsec · point, pica |
| Area | Metric · Imperial · Astronomical | cm², m², hectare, km² · in², ft², acre, mi² · AU², ly², pc² |
| Time | Standard · Astronomical | millisecond, second · Julian day, Julian year, Julian century |
| Angle | A display setting rather than a family | degrees, radians, gradians |
Automatic unit conversion
Leave it on and each value appears in the most readable unit of the family you picked — centimeters here, kilometers there, never feet mixed with kilometers. Switch it off and every length stays pinned to the unit you calibrated in. Distance starts out imperial on devices set to the United States and metric everywhere else, and remembers what you choose.
Precision and number format
Length, area and angle each get their own rounding: Auto, or a fixed zero to three decimal places that pads with zeros so columns line up. Numbers can follow your browser’s region, a preset such as 1,234.56 or 1.234,56, or a plain format with no thousands grouping at all. Both settings reach everywhere — canvas labels, dialogs and exports alike — with a live preview beside each one.
There is no nautical or typography family for area; those units exist for length only. Rounding is a display setting: the underlying measurements stay exact, and the CSV export writes them out unrounded.
Know your image
One dialog answers the questions you would otherwise open a second tool for.
Dimensions, format and file size
Pixel width and height, aspect ratio, megapixels, orientation, the file format and the file size — read from the file you actually dropped in, not guessed from its name.
Scale — real size per pixel
Once the image is calibrated, the same dialog reports what a single pixel is worth in the real world, and how wide and tall the whole picture is on the ground.
Organize your work
A picture carrying forty measurements needs more than an undo button.
Layers with show, dim and hide
Shapes are grouped into layers by type. Each layer has a three-way visibility switch — full, dimmed or hidden — and a color taken from presets or a picker, with an Auto option that adapts to light and dark. Hiding a layer disables its tool as well, and says so instead of failing silently. Any single shape can override its layer’s color.
Projects that save themselves
There is no Save button. Inside a project every committed action is stored as you make it, and the project reopens exactly as you left it on any device you sign in from — layer colors, label toggles and comment visibility included.
Undo, redo and keyboard shortcuts
Up to fifty steps of history, from the header buttons or Ctrl+Z and Ctrl+Y. Undo also switches you back to the tool that owns the shape it just changed, so you carry on where you were. Uploading a new image, clearing the canvas or recalibrating starts history over.
When the canvas gets busy, overlapping labels are hidden automatically at low zoom and return as you zoom in — so a crowded drawing stays readable instead of disappearing under a pile of text.
Export your measurements
Turn a project into a file you can send, print or open in another program. Exports are rendered on our servers from a saved project, prepared in the background, and downloaded as soon as they are ready.
PDF measurement report
Choose the paper size and orientation, a title and description, and how the date appears. Pick which detail sections to include — the dialog pre-selects only the shape types your project actually contains, and shows how many of each. The report leads with the annotated image at full width, then lists every measurement type by type, followed by your notes and any magnifier crops.
Annotated image download
Your picture with everything drawn on it: shapes, the calibration baseline, comment markers and labels. Pick PNG, JPEG or WebP, a quality tier for the lossy formats, an output resolution, and how large the labels should be in the exported pixels.
Spreadsheet exportPRO
An Excel workbook with one worksheet per measurement type, laid out to be read rather than parsed.
Raw data exportPRO
A zip of CSV files carrying exact, unrounded values in your calibration unit — the format to reach for when a script, a spreadsheet formula or an AI assistant is going to read them. Needs a calibrated project.
Every export, keptPRO
Generated files are listed newest first and filtered by project, so an old report can be downloaded again without regenerating it.
Any photo, any format
The picture you already have is usually the picture you want to measure.
Phone photos and scans convert automatically
JPEG, PNG, WebP and GIF open as they are. HEIC and HEIF straight off an iPhone, and TIFF out of a scanner, are converted in your browser as they load, so a photo you just took is ready to measure without a detour through a converter.
Measure straight on a PDF pagePRO
Start a project from a PDF and choose which page to use — the natural route for a scale drawing or a plan set that never existed as a photo.
Anything that is not an image, or is larger than the upload limit, is rejected with a message that says why rather than failing halfway through.
Private by design
The strongest thing we can say about your images is that most of the time we never receive them.
- Without an account, Amplia runs entirely in your browser. The image you measure never leaves your device — there is no upload step, because there is nothing to upload.
- Saving a project is the moment that changes: the image and its measurements go to storage so the project can be reopened on another device and shared. That is a step you take deliberately, not a default.
- A project and its image can be deleted permanently at any time. Deleting your account removes your profile, your projects and your files, and any usage statistics already collected are irreversibly stripped of every identifier.
- Product analytics are tied to a random identifier kept in your browser’s storage — not a device fingerprint — and clearing that storage resets it. Google Analytics runs under Consent Mode v2 with a choice on your first visit, and choosing essential only keeps it cookieless.
None of it is sold, and none of it is used for advertising.
Works on any device
One tool, on whichever screen is closest to the thing you are measuring.
Nothing to install
Amplia is a web application. Open a link and start measuring — no download, no plugin, no app store, no update to postpone.
Built for fingers as well as a mouse
Pinch with two fingers to zoom, or roll the wheel toward the cursor on a desktop. Tap a point on a touch screen and you get a drag handle with a live copy of the area beneath your finger, so what you are aiming at is not hidden by what you are aiming with.
A layout per screen size
The tools panel is a sidebar on a desktop and collapses to an icon bar on a tablet or phone, leaving the canvas the whole screen.
Frequently asked questions
?Is Amplia really free?
The measuring is. Loading an image, calibrating it and using the Line, Polyline, Polygon, Circle, Angle and Comment tools costs nothing and needs no account. A free account adds saved projects, sharing and exports, with limits on how many you can generate each month. PRO raises those limits and unlocks the tools marked PRO on this page.
?Do I need an account?
Not to measure. The workspace opens with a sample image already loaded, and you can replace it with your own photo and start right away. An account is needed to save a project so it survives closing the tab, to share it, and to generate PDF, image or data exports — those are rendered on our servers, so there has to be a saved project to render.
?What image formats and sizes work?
The usual web image formats, plus HEIC and HEIF from iPhones and TIFF from scanners, which are converted automatically as they load. A project image can be up to 10 MB. PDF pages can be used as the source too, on a PRO plan.
?Do I have to calibrate before every tool works?
Before every tool but one. Lengths, perimeters and areas mean nothing without a scale, so those tools wait for calibration. Angles do not depend on scale, so the Angle tool is live as soon as your image is.
?Is my image uploaded anywhere?
Not while you are measuring as a guest — everything happens in your browser and the file stays on your device. Saving a project uploads it so the project can be reopened elsewhere and shared, and you can delete it permanently whenever you want.
?Can I show a measurement to someone who has no account?
Yes. Turn on the public link for a project and anyone holding the link can open it read-only — image, scale and every measurement, with pan and zoom. Turning the switch back off kills the link on the spot.
?Which languages does the app support?
Fourteen: English, German, Portuguese, Brazilian Portuguese, French, Spanish, Italian, Japanese, Indonesian, Traditional Chinese, Korean, Polish, Turkish and Dutch. The picker sorts itself by your browser’s language preferences and remembers what you choose.
Try it on your own photo
The tool opens with a sample image already in it, so you can watch calibration work before you go hunting for a picture of your own. No account, no install.