The Aspect Ratio & Screen Resolution Calculator determines proportional display geometry, greatest common divisor ratios, and scaled resolution dimensions for video production, UI layouts, and graphic design.

### Mathematical Geometric Formulas - Greatest Common Divisor (GCD): Simplifies horizontal width ($W$) and vertical height ($H$) using Euclid's algorithm: $$\text{Divisor} = \gcd(W, H)$$ $$\text{Simplified Ratio} = \frac{W}{\text{Divisor}} : \frac{H}{\text{Divisor}}$$ - Decimal Aspect Ratio: Evaluates the width-to-height proportion: $$\text{Decimal Ratio} = \frac{W}{H}$$ - Total Megapixels: Computes total raster pixel volume: $$\text{Megapixels (MP)} = \frac{W \times H}{1{,}000{,}000}$$ - Proportional Scaling: Calculates matching target height for any scaled width: $$\text{Scaled Height} = \text{round}\left(\frac{\text{Target Width}}{\text{Decimal Ratio}}\right)$$

### Worked Numeric Example Consider scaling standard 1080p Full HD video to 4K Ultra HD: - Input Dimensions: $1920 \times 1080$ pixels - Target Width: $3840$ pixels - Calculated Metrics: - Greatest Common Divisor: $\gcd(1920, 1080) = 120$ - Simplified Aspect Ratio: $1920/120 : 1080/120 = 16:9$ (Standard Widescreen) - Decimal Aspect Ratio: $1920 / 1080 \approx 1.778$ - Total Pixel Count: $2{,}073{,}600\text{ pixels}$ ($2.07\text{ MP}$) - Scaled Dimensions: $3840 / 1.7778 = 2160\text{ pixels}$ ($3840 \times 2160$, 4K UHD)

### Client-Side Processing Note All aspect ratio reductions, pixel scaling, and dimension calculations run purely inside your web browser with zero remote network calls.