I can try ...
Ok, so you have a £5,000 account, and let's say (for the sake of this example) that you're trading EUR/USD (always round numbers, there, in US$, so it's a convenient example). And let's further assume that you've worked out that you want to expose to risk no more than 1% of your account on any individual trade - generally a good starting point, for many people.
So, you're looking at EUR/USD and along comes your set-up, and you want to enter a trade. Let's say a long trade: you think the Euro will strengthen against the dollar/the dollar will weaken against the Euro. You think the EUR/USD price will rise.
You want to risk no more than £50 of your account on this trade (being 1% of £5,000), so you want the distance from your entry-point to the stop-loss - if it all goes pear-shaped on you - to represent no more than £50 damage.
Let's say that for whatever reason you decide this trade needs a stop-loss of 25 pips. That means that if the price moves 25 pips against you, you've decided (at the time of placing the trade) that it wasn't a good entry after all, and you no longer want to be in the trade. So you want 25 pips to represent £50 (which means $65.67, at today's exchange-rate), and that comes to $2.62 per pip. A minilot (10 microlots) of EUR/USD works out at $1 per pip, so you can afford to trade 2.62 minilots (26.2 microlots). This is just arithmetic: a minilot's movements win/lose you $1 per pip (always - regardless of leverage), so with a 25-pip stop-loss, if it all goes wrong and your trade is stopped out, a one-minilot trade would cost you $25: you're actually willing to risk $65.67, so that's going to represent 2.62 minilots (65.67 divided by 25).
You might later move the stop-loss during the trade, to reduce risk or to lock in some profit (we hope), but you won't ever move it away from the original price, increasing your risk to more than 1% - kind of a "golden rule", there - because you've already decided on opening the trade that a 25-pip loss will take you out of it, and you stick to that.
So you're going to buy 2.62 minilots of EUR/USD, knowing that you're selling it again, if you have to (i.e. if you get stopped out) after a 25-pip loss.
Note that so far, your leverage has not affected anything we've mentioned.
One lot of EUR/USD costs $100,000 to buy (always - by definition), so 2.62 minilots of EUR/USD therefore costs $26,200. And that's where leverage comes in, because you're ("effectively, kind of") borrowing 99% of the money temporarily, to buy it (if you use 1:100 leverage) so you need only a theoretical $262 in your account to buy those 2.62 minilots (I say "theoretical" because in reality your broker will require you to have a bit more than just $262, to cover the risk of unforeseen accidents, but with sensible 1% risk-exposures that doesn't matter to you, anyway). Your $262 is not all at risk, provided you enter a 25-pip stop-loss with the trade: only $65.67 of it (£50 of it) is at risk. Note that this depends on your stop-loss being acted on by your broker, which can occasionally be a problem for people "trading the news". But we're assuming for the moment that you're not trading at 1.25pm UK time on the Friday that the US non-farm payrolls figure is about to be announced and that there are no "special/unusual risks" in trading whenever you're trading.
A cumbersome explanation, I know.
Alternatively, you can call your account $6,567 rather than £5,000 in the first place, and work the whole thing out in dollars from the start. (That works neatly when you're trading EUR/USD, not so conveniently when you're trading CHF/JPY!).
There's a free position-size calculator that you can use, here: Position Size Calculator: Free Online Forex Position Sizing Calculator (note that leverage isn't one of its required inputs).
Does that actually help, or have I made it more confusing??? :8: