You can search the internet about stop loss, and there are several of them, the formula and calculation are there, if you have to do it manually, then you have to recalculate it every time. I suggest, you buy Metastock version 11 and get Reuters data feed for Asian market, data feed for other markets are available for a fee. As for stop loss. Metastock has several stop loss included on the package. I use chandelier & Intellistop and base on volatility, on the chandelier, you can adjust the time perdiod and the ATR factor. So you are serious about trading, buy this charting software and feed.