Aspect Ratio Calculator

Aspect Ratio Calculator

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Your Aspect Ratio is: 16 : 9

ARCalc Chrome Extension

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ARCalc Firefox Extension

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Instructions

1. Pop in your original width (W1) & height (H1) values on the left. You know, the dimensions you're starting with.

2. Now here's the magic: enter either a new width (W2) or new height (H2) on the right. The calculator will figure out the other one for you. Pretty neat, right?

3. Changed your mind? No worries! Tweak the values whenever you want, or just hit to start fresh.

The Math (Don't Panic!)

Let's say you've got a gorgeous photo that's 1600 × 1200 pixels, but uh oh, your blog can only fit 400 pixels wide. What now? Time for some aspect ratio wizardry! ✨

(original height / original width) × new width = new height

(1200 / 1600) × 400 = 300

Boom! Your resized photo is 400 × 300 pixels and looks perfect. No squishing, just pure proportional beauty.

&Pixels

ARCalc is built by &Pixels, a design and development studio crafting thoughtful tools and experiences. If you need help with this calculator or have a feature request, we'd love to hear from you.

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Frequently Asked Questions

Aspect ratio is the shape of a rectangle: width compared to height. It's written like 16:9 or 4:3. Same ratio = same shape, no matter the size (a 1600×900 and 1920×1080 are both 16:9).
If you know the image dimensions, divide width ÷ height and simplify. Example: 1920×1080 → 16:9. If you paste dimensions into this calculator, it'll do the simplifying so you don't have to pretend you enjoy fractions.
Same deal as any image: the aspect ratio is photo width : photo height. A lot of phone photos are 4:3, while many "full screen" shots are 16:9—but the only way to be sure is to check the pixel dimensions.

After Effects doesn't "change" aspect ratio so much as it changes the composition size or crops/scales your footage.

  • To change the comp: Composition → Composition Settings → Width/Height
  • To fit footage into a new ratio: use Scale (fills, may crop) or Fit options via Layer → Transform

Pro tip: if you stretch it to force a ratio, everyone will know. Don't do that.

Use the ratio that matches where it's going:

  • 16:9 = YouTube, most video players, standard web video
  • 9:16 = Stories/Reels/TikTok (vertical)
  • 1:1 = square posts, thumbnails, grids
  • 4:5 = taller Instagram feed posts
  • 3:2 / 4:3 = common camera/photo ratios

If you're unsure: pick the platform first, then match its native vibe.

An aspect ratio calculator takes width and height (pixels, inches, whatever), simplifies them into a clean ratio (like 16:9), and often helps you scale up/down without changing the shape. It's basically "don't make me do math" in tool form.
Aspect ratio determines how wide or tall something feels—the overall framing. It affects composition, cropping, how content displays on screens, and whether your design looks cinematic, square, or "why is everyone's head cut off?"

An aspect ratio isn't a pixel size by itself—it's just a shape. To get pixels, you need one dimension:

  • If ratio is 16:9 and you choose width 1920, height = 1920 × 9 / 16 = 1080
  • If you choose height 900, width = 900 × 16 / 9 = 1600

Pick one number, the ratio gives you the other.

That's 1:1 (square). The most symmetrical ratio. The golden retriever of aspect ratios—friendly and works everywhere.

You can't convert a ratio directly into inches without a real-world size or DPI/PPI. Ratio only tells the shape.

Example: 4:3 could be 4in×3in, 40in×30in, or 4000px×3000px—same ratio, totally different size.

In Avid Media Composer, you'll typically adjust aspect ratio via project/format settings and how clips are scaled/reframed in the timeline:

  • Make sure your project format matches your delivery (e.g., 1080p/4K, 16:9).
  • Use Reformat / FrameFlex / Resize tools (depending on version/workflow) to fit, fill, or crop footage into the target ratio.

Translation: set your sequence to the right shape, then decide if your clips should letterbox, crop, or scale.

Aspect ratio + one dimension = a resolution. Common examples:

  • 16:9: 1280×720, 1920×1080, 3840×2160
  • 9:16: 1080×1920, 1440×2560
  • 1:1: 1080×1080, 2048×2048

If you tell the calculator the ratio and your target width (or height), it can generate matching resolutions without warping anything.