Aspect Ratio Calculator
Resize an image, display, or rectangle while preserving its original width-to-height proportion. Choose whether the new width or the new height is known; the calculator solves the other dimension.
How to use this calculator
Enter the known resized dimension, positive whole-number original width and height, and either a positive new width or positive new height.
Review orientation, pixel aspect ratio, crop versus fit behavior, units, and required whole-pixel rounding.
Read simplified aspect ratio, proportional target width, and proportional target height.
Formula
Simplified aspect ratio divides original whole-number width and height by their greatest common divisor. New height = new width × original height ÷ original width; new width = new height × original width ÷ original height.
Worked example
A 1,920 × 1,080 image simplifies to 16:9; at 1,280 px wide the matching height is 720 px.
Assumptions and limits
- Pixels or lengths are square and the rectangle is resized without cropping, stretching, rotation, or nonuniform scaling.
- Aspect Ratio Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- OpenStax: College Algebra 2eAlgebraic, ratio, radical, equation, and function formulas. Reviewed 2026-08-14.
- OpenStax: Prealgebra 2eOfficial formula or method source used by this calculator. Reviewed 2026-08-14.
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Verification
How this calculator is checked
Trust comes from reproducible evidence, not model confidence. You can inspect the formula, assumptions, worked example, and cited sources on this page.
- Versioned calculationFormula logic is kept separate from the interface and covered by automated registry and behavior checks.
- Cited evidenceSources linked for independent checking: 2.
- Transparent AI useAI may assist drafting or adversarial review. Agreement between models is not proof, and no human expert review is claimed unless a named reviewer is shown.
Frequently asked questions
How does the Aspect Ratio Calculator work?
Simplified aspect ratio divides original whole-number width and height by their greatest common divisor. New height = new width × original height ÷ original width; new width = new height × original width ÷ original height.
What information should I enter in the Aspect Ratio Calculator?
Enter the known resized dimension, positive whole-number original width and height, and either a positive new width or positive new height, then verify orientation, pixel aspect ratio, crop versus fit behavior, units, and required whole-pixel rounding.
What should I verify before using this Aspect Ratio Calculator result?
Pixels or lengths are square and the rectangle is resized without cropping, stretching, rotation, or nonuniform scaling.
Last updated 2026-08-25 · solve-width-or-height-v2 · content-2026-08-14 · Published by YunFanLabs