Conversions & SizesFormula-based · Runs in your browser

Aspect Ratio Calculator

Calculate aspect ratios and resize dimensions.

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Calculation steps

Follow what happened from the selected formula to the displayed answer.

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  1. 1

    Formula selected

    The calculator uses the following formula or method.

    New height = new width × original height ÷ original width, or new width = new height × original width ÷ original height.

  2. 2

    Values entered

    Your values are placed into the calculation.

    Enter values to see what is used in this step.

  3. 3

    Result calculated

    The formula or method produces the following result values.

    Results will appear after a successful calculation.

  4. 4

    Answer formatted

    Displayed values are rounded and formatted using each output’s configured precision.

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How it works

Calculate aspect ratios and resize dimensions.

Input query strings and outputs

Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.

Input query strings

4
  • ?width= Width

    Number · Optional · Default: 1,920

  • ?height= Height

    Number · Optional · Default: 1,080

  • ?newWidth= New Width

    Number · Optional · Default:

  • ?newHeight= New Height

    Number · Optional · Default:

Outputs

1
  • result Result

    Text · Primary output

result contains the calculator’s complete rendered result area, including its visible result cards, tables, charts, and messages.

Calculate and resize image dimensions while maintaining proportions

Description

The Aspect Ratio Calculator is a design tool that helps you understand the proportional relationship between an image’s width and height. Whether you are prepping a thumbnail for YouTube, an image for Instagram, or a hero banner for a website, this tool allows you to calculate the base ratio (like 16:9 or 4:3) and instantly find new dimensions for scaling up or down without distorting the image.

Inputs

  • Original Width: The current width of your image in pixels.
  • Original Height: The current height of your image in pixels.
  • New Width / New Height: Enter a value in either field to see what the other dimension should be to maintain the original ratio.

Outputs

  • Aspect Ratio: The simplified ratio (e.g., 16:9).
  • Calculated Dimension: The corresponding width or height for your new size.

Chart

  • N/A: This tool provides direct numeric pixel results.

“Good to Know”

  • Distortion: If you change the width of an image without changing the height proportionally, the image will look “stretched” or “squashed.” This is called “breaking the aspect ratio.”
  • Common Ratios:
    • 16:9: HD Video, Modern Monitors.
    • 4:3: Older TVs, iPad screens.
    • 1:1: Square (Instagram posts).
    • 9:16: Vertical Video (TikTok, Reels).
  • GCD: This tool uses the Great Common Divisor (GCD) to simplify your dimensions into the smallest possible whole-number ratio.

Examples

Example 1: Full HD to 4K

  • Input: Width: 1920, Height: 1080. New Width: 3840.
  • Output: Ratio: 16:9, New Height: 2160.

Example 2: Classic Resolution

  • Input: Width: 800, Height: 600.
  • Output: Ratio: 4:3.

Example 3: Phone Photo

  • Input: Width: 3000, Height: 4000.
  • Output: Ratio: 3:4.
Sources
  • No external reference is listed for this calculator. Its formula and variable definitions are shown above.
Limitations
  • Measurement and sizing conventions can vary. Check the stated conversion basis and any manufacturer-specific size chart.