126844 2014-01-12 08:14:09 -0800 Subpixel Layout: getComputedStyle rounds off fractional pixel values 2014-06-10 19:56:06 -0700 1 1 1 Unclassified WebKit Layout and Rendering 528+ (Nightly build) Mac (Intel) Unspecified RESOLVED WORKSFORME http://codepen.io/desandro/pen/CEfJF InRadar P2 Normal --- 126283 1 desandrocodes zalan jonlee mathias m.goleb+bugzilla simon.fraser webkit-bug-importer zalan oldest_to_newest 966959 0 desandrocodes 2014-01-12 08:14:09 -0800 See example http://codepen.io/desandro/pen/CEfJF The value of getComputedStyle( elem ).width is returned as 199px for an element that has CSS `width: 66.666%`, and it's parent element has `width: 300px`. Other browsers keep the fractional pixel value, i.e. 199.98px. I expected the value to either have the fractional pixel, or round up to the nearest integer, instead of rounding off any fractional pixel value. I imagine this behavior might be by design, as it 199px is the rendered width of the element, and it prevents rounding errors to overshoot the true value. That said, I thought it was worth documenting. I have found that using `calc()` values for `width` produces closer-to-expected values. So for that example, changing width to `calc( 100% * 2 /3 )` returns `200px`. See http://codepen.io/desandro/pen/CKwfd 969674 1 zalan 2014-01-19 18:27:47 -0800 <rdar://problem/15855798> 1014639 2 zalan 2014-06-10 19:56:06 -0700 getComputedStyle( box ).width now returns 199.984375px as expected. This has been fixed by one of the patches while transitioning to subpixel rendering.