16:9, 4:3, 21:9 Resolution Scaler & Canvas Calculator
Calculate corresponding pixel dimensions for standard aspect ratios given width or height constraints for video, broadcast, graphics, and web layouts. Includes GCD ratio reduction, codec macroblock alignment (Mod 2 / Mod 16), and letterbox display simulation.
aspect-ratio: 16 / 9;aspect-[16/9] w-[1920px] h-[1080px]-vf "scale=1920:1080:flags=lanczos"<canvas width="1920" height="1080"></canvas>{"width":1920,"height":1080,"aspectRatio":"16:9"}Multiplier Scale Ladder (1920 × 1080)
Proportionally scaled dimension ladder with megapixels and instant one-click adoption.
| Multiplier Scale | Width (X) | Height (Y) | Total Resolution | Actions |
|---|---|---|---|---|
| 0.25× (Quarter) | 480 px | 270 px | 0.13 MP | |
| 0.33× (One-Third) | 640 px | 360 px | 0.23 MP | |
| 0.5× (Half) | 960 px | 540 px | 0.52 MP | |
| 0.75× (Three-Quarter) | 1440 px | 810 px | 1.17 MP | |
| 1.0× (Native Base) | 1920 px | 1080 px | 2.07 MP | |
| 1.25× (Upscale) | 2400 px | 1350 px | 3.24 MP | |
| 1.5× (Retina 1.5x) | 2880 px | 1620 px | 4.67 MP | |
| 2.0× (Retina 2x) | 3840 px | 2160 px | 8.29 MP | |
| 3.0× (Super 3x) | 5760 px | 3240 px | 18.66 MP | |
| 4.0× (Ultra 4x) | 7680 px | 4320 px | 33.18 MP |
Standard Aspect Ratios & Technical Reference
An aspect ratio describes the proportional relationship between an image, video, or canvas width and height. It is commonly expressed as two numbers separated by a colon, such as 16:9, 4:3, or 21:9.
The international standard format for HDTV, Full HD (1920×1080), 4K UHD (3840×2160), YouTube video players, and modern consumer computer monitors. Chosen in the late 1980s as the geometric compromise between 4:3 and 2.35:1.
The standard ratio of cathode-ray tube (CRT) television, standard definition broadcasting (NTSC/PAL), classic iPad tablet screens, and retro arcade cabinets (VGA 640×480, XGA 1024×768).
Popularized by panoramic gaming monitors (3440×1440 UWQHD, 2560×1080 UWFHD) and anamorphic theatrical cinematography. Technically defined in consumer monitors as 64:27 (~2.370:1).
Mathematical Formulas & Macroblock Rules
Most video encoders (FFmpeg, H.264 AVC, H.265 HEVC, VP9) require horizontal and vertical dimensions to be divisible by 2 (Mod 2) due to 4:2:0 YUV chroma subsampling. Divisibility by 16 (Mod 16 macroblocks) avoids compression edge artifacts and green padding lines.