How do I check the dimensions of an image?

Drop the file above. Its width and height in pixels appear immediately, decoded in your browser. The tool also converts those pixels to centimetres, millimetres and inches at common print resolutions, so you can read the size in whatever unit a form or print job expects.

How are pixels converted to cm, mm or inches?

Pixels have a physical size only when a print resolution is chosen. Inches equal pixels divided by DPI, and centimetres are inches times 2.54. So 1200 px at 300 DPI is 4 inches, about 10.16 cm. The checker shows the conversion at 72, 150 and 300 DPI so you can pick the row that matches your DPI.

Why does the same image show different cm at different DPI?

Because physical size depends on how tightly the pixels are packed. The pixel count never changes, but at 150 DPI the pixels spread over twice the paper of 300 DPI, so the centimetres double. There is no single 'cm size' for an image until you fix a DPI.

What is the difference between dimensions and resolution?

They describe the same thing from different angles. Dimensions are the width and height, usually in pixels; resolution is that pixel grid as a measure of detail. People say 'dimensions' when they mean the literal size to fit a layout, and 'resolution' when they mean how much detail there is. This tool shows both.

Can I check several images at once?

Yes. Drop a batch and each one expands to its own dimensions and unit conversions, so you can compare them without opening files one by one. Everything stays in your browser.

Do you upload my image to read its dimensions?

No. The file is decoded locally in your browser to measure width and height. Nothing is sent anywhere, so private documents and work files are safe to check here.

Image Dimensions Checker

Check image dimensions in pixels, cm and inches

Drop an image to read its exact width and height in pixels, then see those pixels converted to centimetres, millimetres and inches at common print resolutions. It runs in your browser, so the file is never uploaded.

Drop an image here, or click to choose

JPG, PNG, WebP, GIF, AVIF, BMP, TIFF, HEIC. Read entirely in your browser.

Files never leave your device
Runs in your browser
Free, no signup

How it works

1
Drop an image
Add one file or a batch. Each is decoded in your browser to measure its real width and height in pixels.
2
Read pixels and physical size
See the dimensions in pixels, plus the print size in inches and centimetres at 72, 150 and 300 DPI.
3
Match your requirement
Pick the unit your form or print job uses. If the size is off, resize in pixels or set the DPI to fix it.

What the dimensions checker shows

Pixels plus real-world units

Width and height in pixels, converted to centimetres, millimetres and inches at three common DPIs, the conversion most other checkers leave out.

Honest about physical size

An image has no fixed cm size until a DPI is chosen, so the tool shows the size at each resolution rather than pretending there is one answer.

Read locally, never uploaded

The file is decoded in your browser to measure it. Nothing leaves your device, so it is safe for ID photos and confidential documents.

Where this helps

Forms

Forms that ask for cm or mm

Many ID and exam forms state a photo size in centimetres or millimetres. Read the pixels, find the cm at 300 DPI, and confirm the image matches before uploading.

Planning a print at the right size

See exactly how large your pixels print in inches and cm at 300 DPI, so you order the correct print size instead of guessing.

Design

Fitting a fixed layout slot

When a template needs an image at specific pixel dimensions, check the current size first to know whether to resize, and by how much.

Workflow

Comparing a set of images

Drop several files to line up their dimensions at a glance and catch the odd one that does not match the rest of a batch.

Tips that help

1
On screen, think in pixels
For web, social and app uploads, the dimension that matters is pixels. Centimetres only come into play when you print.
2
A cm size needs a DPI
If a form asks for centimetres, it is assuming a resolution, usually 300 DPI. Use that row in the conversion to read the right size.
3
Lock the ratio when resizing
Changing only width or only height stretches an image. Resize with the aspect ratio locked so the picture stays in proportion.
4
Check before, not after
Read the dimensions before you start editing. Knowing the starting size tells you whether to enlarge, shrink, or leave the pixels alone.

Image dimensions explained: from pixels to centimetres, millimetres and inches

Dimensions sound simple, just width by height, but the moment someone asks for an image 'in cm' or 'in inches', confusion sets in. The honest answer is that a digital image has no physical size until you choose a print resolution. This guide explains how pixel dimensions become physical ones, why the same image can be many different sizes in centimetres, and how to read the number a form or print shop is really asking for. The checker does the maths in your browser, no upload.

Pixels are the native unit

Every digital image is measured natively in pixels: a width and a height, like 1080 × 1350. That is the dimension software, browsers and upload forms read directly, and it is the only size an image truly has on its own.

Check image dimensions in pixels, cm and inches

When a field asks for dimensions and you are working on screen, it almost always means pixels. Social platforms, profile pictures, banner slots and most web forms are specified in pixels because the display is a pixel grid.

So the first thing this checker shows is the exact pixel width and height, decoded from the file. For on-screen use, that is the whole answer.

Turning pixels into centimetres, millimetres and inches

Physical units enter only when the image is printed, and printing needs a resolution. The relationship is one formula: inches equal pixels divided by DPI. Centimetres are inches times 2.54, and millimetres are centimetres times ten.

Worked through: 1200 pixels at 300 DPI is 4 inches, which is 10.16 cm or 101.6 mm. Drop the same 1200 pixels to 150 DPI and they spread to 8 inches, 20.32 cm, twice the size from the very same file, because the pixels are packed half as densely.

This is why a form that wants a photo '3.5 cm wide' must also imply a DPI, usually 300. The checker shows the conversion at 72, 150 and 300 DPI together, so you can read the centimetre or inch size for the resolution your job uses, and resize if the physical size is wrong.

When the dimensions are wrong, what to change

If the pixel dimensions do not fit a layout or a form's pixel limit, the fix is a resize in pixels: set the exact width and height you need, with the aspect ratio locked so nothing stretches.

If the pixels are right but the print comes out the wrong physical size, the pixels are fine and only the DPI tag needs setting, which changes centimetres on paper without touching a single pixel.

And if you only need to know whether the image will fit a target ratio before resizing, the aspect ratio calculator shows the proportions and scales them for you. Reading the dimensions first tells you which of these you actually need.

Frequently asked questions

Honest answers to what people ask before using this tool.

Check image dimensions in pixels, cm and inches

How it works

Drop an image

Read pixels and physical size

Match your requirement