Sorry to keep coming back to this. I'm testing 4 oz tins right now. They are 2 1/2 inches across. I test them for two and a half hours at a time and weigh them after each burn. The issue is that the candles burn faster with each test and so the burn rate decreases. The first burn had them at 25-26 hours. The second, 22-24 hours, the third, 14-21 hours, the fourth, 12-17 hours, and so on. I'm guessing they burn faster b/c the exposed tin helps them melt faster. So, how do I determine total burn time? Do I just manually add up the hours burned and use that? Do I average the burn times? I know I'm probably making this harder than it is, but I'm stumped. I didn't see this topic using the search feature, and I'm feeling like the resident problem child on burn rates! :embarasse If anyone can offer an answer, I'd really, really, appreciate it.