Free Aspect Ratio Calculator от &Pixels

Instructions
1. Pop in your original width (W1) & height (H1) values on the left. You know, the dimensions you're starting with.
2. Now here's the magic: enter either a new width (W2) or new height (H2) on the right. The calculator will figure out the other one for you. Pretty neat, right?
3. Changed your mind? No worries! Tweak the values whenever you want, or just hit reset to start fresh.

The Math (Don't Panic!)
Let's say you've got a gorgeous photo that's 1600 × 1200 pixels, but uh oh, your blog can only fit 400 pixels wide. What now? Time for some aspect ratio wizardry! ✨

(original height / original width) × new width = new height
(1200 / 1600) × 400 = 300

Boom! Your resized photo is 400 × 300 pixels and looks perfect. No squishing, just pure proportional beauty.