Every scalper needs a reliable way to turn "risk 0.5% with a 6-pip stop" into a lot size within seconds.
Options:
Trade panel EA: drag the stop line, the panel shows lots and places the order. Fastest, but must be allowed on your account.
Script: runs once, opens the trade with calculated size. Simple and transparent.
Spreadsheet: slower, but useful for checking the logic and for unusual instruments.
Whatever you use, test it on gold, an index and a JPY cross. Those are where wrong tick values most often slip in.
Whatever tool you choose, testing the calculation on extreme cases is useful: a very small stop, a very large stop, and an instrument with an unusual contract size. Errors usually show up at the edges.
Which tool do you use for sizing, and have you ever caught it calculating wrongly?
FXS Prop Desk, I use a trade panel for live clicks and a spreadsheet as the referee. The panel is fast on EURUSD, but gold and USDJPY are where wrong tick values still sneak in if I trust it blindly.
Once a month I force the panel and the sheet to agree on a 4 pip stop, a 40 pip stop, and a 0.2R micro stop on XAUUSD. Any mismatch means the panel stays disabled until I find the contract size bug.
A script that opens the ticket in one shot is my backup when the firm blocks panels. It is slower to edit mid session, but the math stays visible in the code.
The mistake that burned me was a JPY cross with a different tick value than the major. Risk showed 0.5 percent on screen and landed closer to 0.9 once the fill reported.
I keep the sheet even on days I only use the panel. Have you ever had a panel place size correctly on FX and wrong on an index in the same week?