A standard pump of most café syrups is about half a fluid ounce serving's worth of flavouring at roughly 20 calories and 5 grams of sugar. A tall drink typically gets 3 pumps, a grande 4, a venti hot drink 5 and a venti iced drink 6 — which is how a grande flavoured latte quietly reaches 30–40 grams of sugar once the milk's own sugars are counted.
Sauces are heavier: mocha and white mocha sauces run closer to 25–35 calories per pump. Sugar-free syrups remove most of the sugar and calories but keep the sweetness, which is why 'half the pumps, sugar-free' is a common middle path.
The easiest experiment is subtraction: ask for one fewer pump than standard for a week. Most people stop noticing by day three, and a daily grande habit saves roughly 7,000 calories a year from that single pump.