How to calculate position size quicker?

I use MT5 on my phone and do my charting on a tablet (I use a mouse and keyboard, so no worries).

I notice people using position EAs, but I don’t think I can do that since I don’t have a PC.

Is there an alternative? By the time I calculate the lot size using an online calculator, the price has changed, and I have to redo the calculation.

Numerous online position sizing calculators are accessible, which can save you time and effort, particularly if you’re actively trading. It’s essential to select a reliable calculator that employs a robust position sizing formula.