Aspect Ratio Calculator

Use the form below to calculate the missing value for a particular aspect ratio. This is useful, for example, when resizing photos or video.

W1 H1	=	W2 H2
Common ratios: 7680 x 4320 (8K UHDTV) 5120 x 2880 (5K, iMac with retina screen) 3840 × 2160 (4K UHDTV) 2048 x 1536 (iPad with retina screen) 1920 x 1200 (WUXGA) 1920 x 1080 (HD TV, iPhone 6 plus) 1334 x 750 (iPhone 6) 1200 x 630 (Facebook) 1136 x 640 (iPhone 5 screen) 1024 x 768 (iPad) 1024 x 512 (Twitter) 960 x 640 (iPhone 4 screen) 800 x 600 728 x 90 (Common web banner ad size) 720 x 576 (PAL) 640 x 480 (VGA) 576 x 486 (NTSC) 320 x 480 (HVGA)

Round results to the nearest whole number

Your aspect ratio is: ? : ?

Example

Show sample image

Image source: How to handle ratio mismatches:

Instructions

1. Enter the values for the original width (W₁) & original height (H₁) on the left.
2. Enter either a new width (W₂) or new height (H₂) on the right to calculate the remaining value.
3. Change any of the values at any time, or reset them to the starting values.

Formula

Say you have a photo that is 1600 x 1200 pixels, but your blog only has space for a photo 400 pixels wide. To find the new height of your photo—while preserving the aspect ratio—you would need to do the following calculation:

(original height / original width) x new width = new height

(1200 / 1600) x 400 = 300