```
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
	NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:@"Hello. That is a test attributed string."];
	[str addAttribute:NSFontAttributeName value:[NSFont fontWithName:@"HelveticaNeue-Bold" size:24.0f] range:NSMakeRange(20, 10)];
	
	CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)str);
	CGSize targetSize = CGSizeMake(320, CGFLOAT_MAX);
	CGSize fitSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0, [str length]), NULL, targetSize, NULL);
	CFRelease(framesetter);
	NSLog(@"%f, %f", fitSize.width, fitSize.height);
}
```

That gave me

`2013-09-24 20:30:21.985 Test[24351:303] 247.187437, 28.000000`

It's definitely working and definitely using the right height.