Less caffeine per cup than brewed coffee
Instant coffee is made from brewed coffee that has been dried into soluble granules. The USDA FoodData Central entry for instant coffee prepared with water lists 62 mg of caffeine in an 8 oz cup and 47 mg in a 6 oz cup. That is about two-thirds of the caffeine in the same volume of brewed coffee.
The lower caffeine is not because the serving is weaker in flavour; it is a result of the processing. Instant coffee typically uses Robusta beans, which are higher in caffeine, but the extraction and drying steps mean less caffeine ends up in the final cup compared with fresh drip coffee.
Easy to control
Instant coffee is one of the easiest caffeine sources to titrate. You can use a smaller spoon, half a packet, or a weaker concentration to land on a precise dose. That makes it useful for people who want a predictable, low-to-moderate caffeine intake without brewing a full pot.
A standard 8 oz cup at 62 mg is below the 200 mg single-dose threshold EFSA notes can affect sleep in some adults. Even two cups is 124 mg, still well below the threshold for most people.
Common serving sizes
A rounded tablespoon of instant coffee granules usually makes an 8 oz cup. Some brands sell single-serve packets that contain more granules and can produce a stronger 8 oz cup or a larger 10–12 oz mug. If you use two packets or a heaped spoon, the caffeine can approach brewed-coffee levels. Check the packaging for the recommended serving weight if you want a precise dose.
Source
The caffeine figures are from USDA FoodData Central, instant coffee prepared with water, checked 19 September 2026.