# How do I work out a new constrained scale height based on a new width?

This is super simple I guess but my mind has gone blank.

I have these dimensions below, and I am trying to scale this rectangle to 610 wide

Width 560 Height 315

From these figures, how do I work out the percentage to scale the height so the rectangle is still at the same aspect ratio?

Thanks

Think I got it...

560 / 100 = 5.6

610 / 5.6 = 108.92

Since $\frac{610}{560} \doteq 1.089$, you have to scale by approximately $8.9$% (from 100% to 108.9%).