# Aspect Ratio Calculator

Calculate the aspect ratio of any dimensions and find the correct width or height to maintain proportions when resizing images, videos, or screens.

## What this calculates

Need to resize an image or video while keeping proportions? Enter the original dimensions to find the aspect ratio, then enter either a new width or height to calculate the other dimension automatically. Works for images, videos, screens, and print layouts.

## Inputs

- **Original Width** (px) — min 1
- **Original Height** (px) — min 1
- **New Width (or 0 to calculate)** (px) — min 0 — Enter 0 to calculate from new height
- **New Height (or 0 to calculate)** (px) — min 0 — Enter 0 to calculate from new width

## Outputs

- **Aspect Ratio** — formatted as text
- **Ratio (decimal)**
- **Calculated Width**
- **Calculated Height**

## Details

Common aspect ratios:

  - 16:9: Widescreen TV, YouTube, most monitors (1920x1080, 2560x1440)

  - 4:3: Classic TV, iPad, many projectors

  - 21:9: Ultrawide monitors, cinematic

  - 1:1: Instagram posts, profile pictures

  - 9:16: Vertical video (TikTok, Instagram Stories, Reels)

  - 3:2: DSLR photos, MacBook displays

## Frequently Asked Questions

**Q: What aspect ratio should I use for YouTube?**

A: YouTube's standard aspect ratio is 16:9. This includes resolutions like 1920x1080 (1080p), 2560x1440 (1440p), and 3840x2160 (4K). YouTube will add black bars (letterbox or pillarbox) to videos that do not match 16:9.

**Q: How do I maintain aspect ratio when resizing?**

A: To maintain proportions, you must scale both width and height by the same factor. This calculator does that automatically: enter one new dimension and it calculates the other to preserve the original ratio.

**Q: What is the difference between 16:9 and 16:10?**

A: 16:9 is the standard for TVs and most monitors. 16:10 is slightly taller and was common in older computer monitors. 16:10 is preferred by some for productivity because it gives more vertical screen space.

**Q: What aspect ratio do phones use?**

A: Modern smartphones typically use ratios between 18:9 and 21:9. Older phones used 16:9. When shooting vertical video or photos, the ratio is inverted (e.g., 9:16, 9:19.5).

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Source: https://vastcalc.com/calculators/technology/aspect-ratio
Category: Technology
Last updated: 2026-04-21