Why Does The Reduced Ratio Differ From A Named Format?

Named formats are often rounded labels. The calculator reduces the exact dimensions by their greatest common divisor, so a slightly cropped or nonstandard resolution can produce a different ratio.

What Is The Difference Between Contain And Crop?

Contain keeps the complete source visible and may add empty space. Crop fills the target frame but removes content along one dimension.

Which Rounding Rule Should I Use?

Nearest is suitable for most pixel dimensions. Use an even-number rule when a codec or production workflow requires dimensions divisible by two.

Aspect Ratio Calculator

Calculate dimensions, compare contain or crop framing, animate between formats and export a production resolution ladder.

Source Dimensions

Use the original pixel dimensions to preserve the exact proportion.

Source WidthpxSource Heightpx

Common Ratios

Calculate New Size

Choose which side is known and how the missing pixel value should be rounded.

Missing Dimension

Target WidthpxThis is the side you already know.Rounding Method

Frame Preview

The frame follows the exact source ratio, including uncommon dimensions.

1,920 × 1,080

Reduced Ratio16:91.7778 To 1

Calculated Dimensions3,840 × 2,160Before Rounding: 2,160 px

Contain And Crop Comparison

Preview how the source behaves inside a different output frame.

Comparison Frame

Contain

Shows the entire source. Empty space remains when the ratios differ.

Crop

Fills the output frame. Content beyond the edges is trimmed.

Ratio Motion Lab

Preview a smooth cubic transition between two frame shapes. Loop reverses direction at each endpoint so the motion never jumps.

Start RatioEnd Ratio

1.778 : 1

Transition Position · 0%

Duration · 1.8 Seconds Loop Smoothly

Production Size Ladder

Common widths scaled to the exact source ratio.

Width	Height	Pixels
320 px	180 px	0.06 MP
640 px	360 px	0.23 MP
1,080 px	608 px	0.66 MP
1,920 px	1,080 px	2.07 MP
2,560 px	1,440 px	3.69 MP
3,840 px	2,160 px	8.29 MP

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What Is the Aspect Ratio Calculator?

The Aspect Ratio Calculator reduces any pixel dimensions to their simplest ratio and scales that ratio to a new width or height. A live proportional frame makes portrait, square, widescreen and ultrawide formats easy to compare, while contain and crop views show how one source fits a different target frame. The Ratio Motion Lab smoothly previews a format change without an endpoint jump, and the Production Size Ladder calculates common deliverable widths for the active ratio.

How It Works

Enter the source width and height or choose a common format. Choose whether the target width or target height is known; the other dimension is calculated from the reduced ratio using the selected rounding rule. Use the framing comparison to inspect letterboxing or cropping, animate between two delivery formats, copy the CSS aspect-ratio value, or download the size ladder as CSV.

When to Use It

Use it when resizing images, preparing video deliverables, choosing presentation or social-media dimensions, building responsive layouts, or checking how a source frame will fit a target display.

Frequently Asked Questions

Why Does The Reduced Ratio Differ From A Named Format?: Named formats are often rounded labels. The calculator reduces the exact dimensions by their greatest common divisor, so a slightly cropped or nonstandard resolution can produce a different ratio.
What Is The Difference Between Contain And Crop?: Contain keeps the complete source visible and may add empty space. Crop fills the target frame but removes content along one dimension.
Which Rounding Rule Should I Use?: Nearest is suitable for most pixel dimensions. Use an even-number rule when a codec or production workflow requires dimensions divisible by two.

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