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Print Size Calculator — Pixels to CM/Inches at Any DPI

← Darkroom IsleThe Creative Island · Island 12

How big can I print this? Pixels → cm/inch at any DPI — both directions.

How to use this tool

  1. Enter your image's pixel dimensions and the print DPI (300 for professional print).
  2. Read the maximum print size in cm and inches — with a quality verdict.
  3. Or reverse it: enter a target width in cm to learn the pixels you need.

Example

3000 × 2000 px at 300 DPI → 25.4 × 16.9 cm — a crisp A4-ish print. To print 21cm wide at 300 DPI you need 2,480 px — so a 3000px file has room to spare, while an 800px screenshot does not.

The formula

inches = pixels ÷ DPI  |  cm = inches × 2.54  |  pixels = cm ÷ 2.54 × DPI

What the result means

DPI is the density argument of the print, not a property of the file — the same pixels print bigger at 150 DPI and sharper at 300. 300 DPI is the professional standard viewed at arm's length; large posters tolerate 150 because distance forgives softness.

Frequently asked questions

Is 300 DPI always necessary?

For photos and brochures, yes. For billboards, no — viewed from 20 meters, 30 DPI can pass. Match DPI to viewing distance.

My file says 72 DPI — is it bad?

That tag is metadata, not destiny. Change the DPI interpretation and the same pixels print at a different size — which is exactly what this calculator shows.

What size file do I need for an A4 photo print?

A4 is 21 × 29.7 cm; at 300 DPI that's 2480 × 3508 px — about 8.7 megapixels.

Is anything uploaded?

No — pure arithmetic, in your browser.

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Privacy & data: this tool runs entirely in your browser — nothing you type is uploaded, saved or sent anywhere. · Disclaimer: your images are opened and processed by your own browser only — files never leave your device, and originals are never modified. · Privacy Policy · Disclaimer
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Image Dimension Checker — Size, Ratio & Megapixels

← Darkroom IsleThe Creative Island · Island 12

Drop in any image — see width, height, exact ratio, megapixels and file size at once.

How to use this tool

  1. Choose any image from your device.
  2. Read the full report: dimensions, simplified ratio, megapixels, format, file size and max print size.
  3. The image preview confirms you're inspecting the right file.

Example

A photo reports 4032 × 3024, ratio 4:3, 12.2 MP — the classic smartphone shot. At 300 DPI it prints up to 34 × 26 cm (13×10 inch), and as a full-width web image it is three times wider than needed: resize to 1200px and save the bandwidth.

The formula

ratio = W:W÷gcd(W,H) · megapixels = W × H ÷ 1,000,000 · print cm = pixels ÷ 300 DPI × 2.54

What the result means

The dimension report answers the three questions every image task asks: is it the right shape (ratio), is it big enough for the job (pixels → print size at 300 DPI), and is it heavier than it needs to be (KB per pixel). A 12 MP photo on a webpage is a delivery truck carrying one letter.

Frequently asked questions

What do I check before uploading a form photo?

Two numbers from this report: the pixel dimensions (some forms demand minimums like 132×170) and the KB size (many cap at 20–100KB — the compressor bench handles that).

What counts as 'high resolution'?

For screens, anything at or above the display size is perfect. For print, use the DPI line: 300 DPI is professional print; 150 DPI is usually acceptable for large posters viewed from distance.

Why does my 12MP photo look worse than a 6MP one?

Megapixels measure quantity, not quality — lens, sensor and compression decide quality. Two very different questions.

Is my image uploaded?

No — it's opened locally by your browser; the report is generated on your device.

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Image Converter — JPG to PNG, PNG to JPG, WebP

← Darkroom IsleThe Creative Island · Island 12

JPG to PNG, PNG to JPG, anything to WebP — converted locally, no upload queues.

How to use this tool

  1. Choose your image (JPG, PNG or WebP in).
  2. Pick the target format — and a background color if a transparent PNG is heading to JPG (JPG can't hold transparency).
  3. Press Convert & download.

Example

A 1.8 MB PNG screenshot → WebP at 90% quality: typically ~200 KB, pixel-crisp, and supported by every modern browser. A transparent logo PNG → JPG comes out on the white background you chose.

The formula

canvas re-encode: image → canvas → toBlob(target format, quality)

What the result means

Each format has a job: JPG for photographs, PNG for crisp graphics and transparency, WebP for the best of both at 25–35% smaller than JPG. Converting transparent PNG to JPG 'flattens' it onto your chosen background — that's why the color picker exists.

Frequently asked questions

Does converting reduce image quality?

JPG and WebP re-compress at the quality you choose (90 here keeps things visually clean). PNG conversion is lossless — identical pixels, different container.

Can it convert to WebP for my website?

Yes — and you should: WebP cuts 25–35% off JPG sizes with the same look, and every modern browser supports it.

What about HEIC (iPhone) photos?

Modern browsers decode HEIC in file inputs on most platforms; if yours doesn't, export the photo as JPG from your gallery first.

Are my files uploaded?

No — conversion happens entirely in your browser.

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Image Cropper — Ratios & Passport Sizes, In-Browser

← Darkroom IsleThe Creative Island · Island 12

Crop to the ratio you need — square for profiles, 16:9 for video, 3.5:4.5 for passports — position it, download it.

How to use this tool

  1. Choose your photo — the preview shows the live crop.
  2. Pick the ratio: square, portrait, video, or exact passport standards (35×45mm is the Bangladesh/India standard).
  3. Slide the vertical position to frame the face where it should be, then download.

Example

Passport applications: select Passport 35×45mm, position the face center-top, download — the file comes out at 413×531px, which prints at exactly 35×45mm at 300 DPI.

The formula

crop window = largest rectangle of the chosen ratio that fits inside the photo, centered horizontally, slider-controlled vertically

What the result means

Cropping to a ratio is what official forms and social platforms actually enforce — they take your square or your 16:9 whether you chose it or not. Doing it yourself means the subject stays framed instead of guillotined. Passport crops come out at 300 DPI-ready pixels, so printing shops get an exact file.

Frequently asked questions

Can I crop to a free size, dragging corners?

This bench crops by fixed ratios — deliberately, because ratios are what forms and platforms demand. Free-form crops belong in a full editor.

Is 35×45mm the right passport size for Bangladesh?

Yes — the standard Bangladesh/India passport photo size (the US uses 2×2 inches instead, also in the list). Always double-check the specific form's instructions before printing.

Does cropping reduce quality?

No — it cuts pixels away, it doesn't stretch them. The remaining area is full original resolution.

Are my photos uploaded?

No — the crop happens on a canvas in your browser and the download is generated locally.

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Image Resizer — Exact Pixels or Percentage, In-Browser

← Darkroom IsleThe Creative Island · Island 12

Resize to exact pixels or a percentage — ratio kept or broken, your call.

How to use this tool

  1. Choose your image — its current size fills the width/height boxes.
  2. Type new pixel dimensions, or a percentage to scale. With Keep ratio on, changing width auto-computes height from the W:H fields proportionally — type width, then height follows your ratio math if you keep ratio on (or paste both).
  3. Press Resize & download — grab PNG or JPG.

Example

A 4000×3000 photo → 1200×900 (30%) for email and web: identical framing, one-ninth the pixels, loads instantly on mobile data.

The formula

new pixels = old × scale%; keeping ratio means height = width ÷ (original W ÷ original H)

What the result means

Downscaling is lossy-but-forgiving: a 30% resize looks nearly identical at screen size and saves massive bandwidth. Upscaling is the honest limit of this bench — it makes bigger files, not more detail. For pixel-perfect framing changes, crop instead of resize.

Frequently asked questions

Is my image uploaded anywhere?

No — resizing happens on a canvas in your browser; the download is generated locally.

What's the best size for web images?

1200px wide covers most full-width blog images; 600–800px for content images. Pair with the compressor for the final byte size.

Why does my upscaled image look soft?

Scaling up spreads existing pixels thinner — no algorithm in a browser can invent the detail that was never captured.

PNG or JPG for the download?

JPG for photos (smaller), PNG for screenshots, text and anything needing transparency.

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Image Compressor — Shrink JPG Files in Your Browser

← Darkroom IsleThe Creative Island · Island 12

Drag in a photo, choose a quality — or a target size like 20KB for form uploads — and download the smaller version. Nothing uploads.

How to use this tool

  1. Click Choose an image and pick your photo.
  2. Either set the quality slider, or type a target size in KB (e.g. 20 for online form uploads) and let the tool chase it.
  3. Press Compress — preview the size, then download. Your original file is never modified.

Example

A 3.5 MB phone photo compressed at 70% quality lands around 300–500 KB with no visible loss. Set target 20KB and the tool drops quality and, if needed, dimensions until the download fits under 20KB — exactly what most government and job-application forms demand.

The formula

canvas → JPEG at chosen quality; for target sizes: quality steps down, then resolution, until the blob fits

What the result means

JPEG compression trades invisible detail for size — at 70–80% quality most photos lose nothing visible and shed 80–90% of their bytes. When a hard KB limit matters, dimension is the bigger lever: a 20KB file at full resolution is mush, but 800×600 at 20KB is clean.

Frequently asked questions

Are my photos uploaded to a server?

No. The image is read by your browser, compressed on a canvas element in your device's memory, and handed back as a download. It never touches a network.

Will this change my original photo?

Never — the tool writes a new file; your original stays exactly as it is.

PNG in, JPG out — why?

JPEG is the efficient format for photos; PNG only wins for flat graphics and transparency. If you need PNG output, use the Image Converter bench next door.

Why is my tiny-target result blurry?

Physics: 20KB can hold only so much picture. If the form allows 50KB or 100KB, use it — the tool will happily use the extra room for sharpness.

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Privacy & data: this tool runs entirely in your browser — nothing you type is uploaded, saved or sent anywhere. · Disclaimer: your images are opened and processed by your own browser only — files never leave your device, and originals are never modified. · Privacy Policy · Disclaimer
Read more
Post a Comment
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