A tablespoon of onion powder equals about a medium sized onion, which would be about a cup, chopped. So, a tablespoon.
1 tablespoon dried minced onion = 3 tablespoon fresh minced onion
1 tablespoon dried minced onion = 3 tablespoon fresh minced onion
On average, 1 chopped onion weighs about 150 grams. However, this can vary depending on the size of the onion and how finely it is chopped.
For rosemary, the ratio is three to one, fresh chopped to dried. So if your recipe calls for 2 tsp. of dried rosemary and you would rather use fresh, you will need three times as much, or two tablespoons of fresh chopped rosemary leaves.
One small onion is a bit bigger than the size of a golf ball, while medium onions are about the size of an apple, perhaps a bit smaller. A golf ball has a diameter of 42.67mm, so let's say a small onion is 45mm. A medium one would be about 70. 70 / 45 = 1.55 One medium onion equals approximately 1.5 small onions.
1 teaspoon onion powder = 1 tablespoon dried onion flakes (minced onions) according to http://www.foodsubs.com/Onionsdry.html. So, 4 tablespoons of minced onion would be 4 teaspoons of onion powder
I just weighed one cup of chopped onion: 4 ounces.
In general you should halve the quantity when using a dried herb. This is because a lot of the fresh herb is water, and the flavour is concentrated when you dry it.
Onion salt tastes like "salty onion". Onion powder just tastes like "onion". I use both onion and garlic powder a lot, but have never used either onion salt or garlic salt, so I can use salt independently (control the amount).
General rule of thumb is 1/2 the amount of dried herbs. So 1/8 of a cup of dried basil is equal to 1/4 cup fresh
1/8 teaspoon onion powder equals 1 tablespoon minced onion also read as this: 1/8 teaspoon onion powder equals 1/16 cup of minced onion