Aspect Ratio Converter

Calculate letterbox, pillarbox, and crop dimensions between aspect ratios.

Source Width

Source Height

Target Ratio Width

Target Ratio Height

Tab to move between fields

Letterbox Bar Height

0 px

Pillarbox Bar Width300 px

Crop Width1,920 px

Crop Height823 px

Image Retained76.2%

Pixel Loss493,440

How to Use This Calculator

Enter the Source Width and Source Height in pixels — the resolution of your original footage.
Input the Target Aspect Ratio (e.g., 16:9, 2.39:1) to see how your image fits the new frame.
Review Letterbox Bar Height (px) to see top/bottom padding needed for widescreen formats.
Check Pillarbox Bar Width (px) for side padding when converting to narrower ratios.
Use Crop Width and Crop Height (px) if you prefer to fill the frame by trimming edges.
Image Retained (%) tells you how much of the original frame survives the conversion.

What each input means

Source Width: Width of the source video in pixels.
Source Height: Height of the source video in pixels.
Target Ratio Width: Width component of target aspect ratio (e.g., 21 for 21:9).
Target Ratio Height: Height component of target aspect ratio (e.g., 9 for 21:9).

Identify Input Parameters
4 parameters
Source Width = 1920, Source Height = 1080, Target Ratio Width = 21, Target Ratio Height = 9 = 4 input(s) provided
Calculate Letterbox Bar Height
Letterbox Bar Height = abs(letterboxHeight)
0 = 0
Calculate Pillarbox Bar Width
Pillarbox Bar Width = abs(pillarboxWidth)
300 = 300
Calculate Crop Width
Crop Width
1920 = 1920