Aspect Ratio Calculator

Calculate aspect ratio, resize dimensions and scaling percentage while preserving proportions

Your result will appear here.

About the Aspect Ratio Calculator

Aspect ratio describes the proportional relationship between width and height. It is used for screens, images, video frames and printed layouts because it preserves shape even when the actual dimensions change.

A 16:9 image can be small or large while still having the same aspect ratio. Stretching only one dimension breaks that proportion and distorts the content.

How to Use the Aspect Ratio Calculator

  1. Enter width and height.
  2. Calculate the simplified width-to-height ratio.
  3. If resizing, enter one target dimension and solve for the other while keeping the same ratio.
  4. Keep pixel dimensions separate from physical screen size unless you are also using resolution or pixel-density information.

How the Calculation Works

Aspect ratio = width ÷ height and is commonly expressed as a simplified pair such as 16:9.

To preserve the ratio during resizing, new height = new width × original height ÷ original width, or new width = new height × original width ÷ original height.

Worked example

Aspect Ratio Calculator Worked Example

1920×1080 image

1920:1080 simplifies by dividing both numbers by 120, giving 16:9. If resized to 1280 px wide, height = 1280×1080÷1920 = 720 px.

Result guide

Understanding Your Aspect Ratio Calculator Result

The ratio tells you shape, not total resolution. Two 16:9 displays can have very different pixel counts, physical sizes and image sharpness.

Before you rely on the answer

Assumptions and Limitations

  • Width and height use the same type of unit.
  • The intended resize keeps proportions unchanged.
  • Cropping and non-square pixels are outside the basic ratio unless explicitly modeled.

Practical tip

Using This Result in Practice

When fitting media into a fixed container, decide whether you prefer letterboxing, cropping or distortion. Preserving aspect ratio prevents distortion but may leave unused space or require trimming.

Related calculations

Useful Calculations to Continue With

If you know display width and height or diagonal and want physical screen dimensions, use the Screen Size Calculator.

For display-specific width, height and ratio relationships, use the Screen Aspect Ratio Calculator where appropriate.

Common questions

Aspect Ratio Calculator FAQ

What does 16:9 mean?

For every 16 equal units of width, the image or screen has 9 equal units of height.

Does aspect ratio tell me resolution?

No. It describes proportion only; many resolutions can share the same ratio.

How do I resize without stretching?

Change one dimension and calculate the other from the original width-to-height proportion.