I'm afraid I weigh the foods but after that I do it the really quick way - I use Nutracheck (it's a diet app) and I put in the foods I'm having - however many grams of carrot, courgette, cauliflower etc and it tells me the carbs in each, and the total for the meal.
(For home made recipes there's a section where I can add those, so that I can include a portion with a meal).
It is a paid for app but thyee may be free versions of a similar thing available.