How do you calculate your potential profit or loss before entering a trade?

Before I touch the order button I run the numbers through a proper calculator rather than doing it in my head. Mental math under market pressure is how mistakes happen and I learned that the hard way after a couple of trades where I underestimated the actual dollar impact of a move. Now it is a non-negotiable step in my pre-trade routine. I punch in the pair, lot size, entry, and target and see the exact figure before anything else.https://roboforex.com/beginners/start/profit-and-loss-calculator/forex/ has become my default for this because it handles the currency conversion automatically and the layout is clean enough that I can run multiple scenarios quickly without getting confused between inputs.