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