Aspect Ratio Calculator

Resize calculator: keep image and video aspect ratio in any pixel size

A simple calculator for aspect ratios and proportional dimensions.

This app does not edit or export images or videos. It only calculates the numbers you need before you resize in your image editor, video editing app, or design tool.

★ What it does ★

• Keep-ratio dimension calculator
Enter the original width × height, then type the new width OR the new height — the other value is calculated instantly so the aspect ratio stays the same.

• Automatic aspect ratio simplification
1920×1080 → 16:9
1080×1080 → 1:1
3840×2160 → 16:9
Any pixel dimensions are reduced to the simplest ratio.

• 6 popular aspect ratio presets
16:9 (Full HD, 4K, widescreen video)
4:3 (classic display, tablet)
1:1 (square posts, profile pictures)
9:16 (vertical video, mobile-first content)
21:9 (ultrawide, cinematic)
3:2 (standard photo)

• Quick width ↔ height swap
Flip portrait and landscape with one tap.

★ What it does NOT do ★

✗ No image editing
✗ No video conversion
✗ No file export
✗ No cloud upload
This is purely a number calculator. Do the actual resizing in your editor of choice.

★ Who is it for? ★

- Video editors who need to plan target resolutions before rendering
- Designers preparing banners, thumbnails, posters
- Photographers matching print or social media dimensions
- Developers and UI/UX designers checking layout numbers
- Anyone who needs the exact pixel size that keeps an aspect ratio

★ Why this app ★

✓ Works fully offline — no internet required
✓ Clean Material 3 interface with dark mode
✓ Small size, fast to open, no account needed

Plan the numbers here, then resize inside your editor. Knowing "1920×1080 scaled to width 1280 gives height 720" in one tap saves you from the calculator on your phone.