Aspect Ratio Calculator
Calculate dimensions, simplify ratios, and find the right size for any platform.
Free & unlimited
Mode
Aspect ratio
Lock
Dimensions
px
Visual preview
1920×1080
Ratio
16:9
Pixels
2,073,600
Megapixels
2.07 MP
Orientation
Landscape
Platform presets
Did you know?
The 16:9 ratio became standard for HDTVs because it's the geometric mean of 4:3 (old TV) and 2.35:1 (cinema).
All processing happens in your browser. No data is sent to any server.
About this tool
- 1
Enter known dimensions
Type in either the width or height you want, along with the target aspect ratio.
- 2
Calculate the other dimension
The tool instantly computes the missing width or height to maintain the ratio.
- 3
Try common presets
Select from popular ratios like 16:9, 4:3, 1:1, or 21:9 for quick calculations.
- Use 16:9 for standard widescreen video and presentations, and 9:16 for vertical mobile content.
- Lock one dimension and adjust the other to find the best fit for your layout without distortion.
- When cropping photos, calculate the target dimensions first to avoid trial-and-error resizing.
- Instant width or height calculation from any ratio
- Preset ratios for video, photo, social media, and cinema
- Custom ratio input for non-standard formats
- Visual preview of the resulting rectangle proportions
- Calculate video export dimensions for YouTube, Instagram, or TikTok
- Determine crop dimensions for photos to fit specific print sizes
- Plan responsive image containers in CSS with correct proportions
- Size graphics for digital signage and displays with unusual aspect ratios
16:9 is the standard for YouTube. Common resolutions include 1920x1080 (1080p) and 3840x2160 (4K).
Enter its width and height and the tool will simplify it to the nearest standard ratio.