Even when you apply the formulas in the linked spreadsheet, you can get into trouble because it seems to assume V_led is fixed. For an example of how quickly t

Even when you apply the formulas in the linked spreadsheet, you can get into trouble because it seems to assume V_led is fixed. For an example of how quickly this can go wrong, see my accepted answer to “Why is my LED circuit drawing 50% more mA than I calculated?” https://electronics.stackexchange.com/questions/572739/why-is-my-led-circuit-drawing-50-more-ma-than-i-calculated https://electronics.stackexchange.com/questions/572739/why-i...