A small tool I built when I got tired of guessing I had some old gold lying around—a few rings, a broken chain. Wanted to sell it but had no idea what it was worth. Took it to a shop, got an offer. Sounded low. Had no way to check. A friend said to look up melt value first. Weight × purity × current price. The stamp tells you the purity. I weighed the stuff, found a calculator online, ran the numbers. The melt value was way higher than what I'd been offered. I went to a different buyer and got a fair deal. Took maybe ten minutes of effort. Should've done it sooner. I ended up building a similar tool—free, no sign-up. You enter weight and purity, it shows the value. Live prices, basic UI. Nothing fancy. Just something I wished had existed when I was standing in that first shop feeling clueless. If you've got old gold and you're curious what it's worth before selling: weigh it, check the stamp, run the numbers. The calculator I built is here. Two minutes and you have a baseline. Doesn't cost anything to check.