I have never been a fan of conversion charts. I have a few reasons for this but the biggest reason is that it allows a user who sees a metric unit to simply convert to what I call, no offence intended, "ye olde imperial units". An effect of charts that convert units is that some Americans get a mindset of " I can just convert that metric unit to imperial. No need to go metric." The problem with this is that, tables allow for folks to think that metric units are equal to a certain imperial equivalent without thinking or visualizing a metric weight or volumn. However, a use I have found for conversion charts is to switch the order of conversion. Instead of metric to imperial, use imperial to metric. Associate familiar imperial unit amounts to a metric equivalent. I have seen this suggested in a few websites, and from my experience, it works great. I now associate my weight in kg, which is another way to help me think in metric. However apart from that, I do not plan on using conversion charts anytime soon.