Measuring one portion of spaghetti can be tricky. Dry pasta can look like a deceptively small portion, but once it's cooked the portion will look larger, since pasta swells as it cooks. A single potion of spaghetti is about 100 g (3.5 oz), according to the website Love Food Hate Waste. Add another 150 g (5.3 oz) worth of sauce, cheese, or other toppings, and you will end up with a single-serving pasta meal consisting of about 250 g (8.8 oz).
Place a kitchen scale on a level surface, such as your worktop.
Add dry spaghetti to the scale until the scale reads 40 to 45 g (1.5 oz). Uncooked pasta will swell as it cooks and will weigh more once it's cooked. Measuring 40 to 45 g (1.5 oz) of dry spaghetti will yield about 100 g (3.5 oz) -- or a single serving -- of cooked spaghetti.
Bring a pot of water to boil on the stove. Add the spaghetti once the water has begun to boil.
Cook the spaghetti for the recommended amount of time indicated on the box or bag of spaghetti. Strain the spaghetti once it has finished cooking.
Use the scale to weigh 150 g (5.3 oz) (in total) of any toppings you choose to have, such as sauce, cheese, vegetables, etc. Pour the toppings on the spaghetti and you will have a single-serving pasta meal consisting of 250 g (8.8 oz).
Make sure you set your scale to measure in grams. If you measure in ounces, you will need to adjust your portion size (1 oz equals 28 g).
A single serving is based on a regular-sized adult, with a moderate level of daily activity. If you are an athlete or have a high level of physical activity, your portion size may need to be increased.