Dry is always more potent, as long as your spices are not old. If you have "fresh" dry ginger, 1 teaspoon would be the right amount to substitute for 2 tablespoons of fresh ginger.
Since ginger is something that loses its potency in dry form very quickly, the best possible answer to this question is "to taste."
About 1% is raw ginger root. Nearer to 2% in ground ginger
103 grams
A one inch piece of fresh, grated ginger (generally yielding 1 tablespoon) equals approximately 1/8 teaspoon ground (dried) ginger. Source: http://www.evitamins.com/healthnotes.asp?ContentID=3602003
1 inch of ginger grated will produce about 4 teaspoons.
Avoid doing this. The proportions unbalance a recipe when you substitute ground for freshly grated ginger.
The amount of ginger root in tablespoons can vary based on how finely it's grated or chopped. Generally, one tablespoon of grated ginger is about 1 inch of fresh ginger root. Therefore, 5 inches of ginger root would roughly equal 5 tablespoons when grated or chopped. However, this is an estimate, and the actual amount may differ depending on preparation methods.
One slice of fresh ginger typically weighs about 1 to 2 grams. In terms of ground ginger, you can use approximately 1/8 to 1/4 teaspoon to equal the flavor of one slice of fresh ginger, depending on your taste preference. Ground ginger is more concentrated, so it's best to start with less and adjust as needed.
6mc
I would just use the same amount because ginger paste is basically really finely miced ginger. Maybe cut down a slight amount if your not a huge fan of ginger.
To substitute powdered ginger for fresh ginger, a general rule of thumb is to use about 1/4 teaspoon of powdered ginger for every 1 tablespoon of fresh ginger. This is because powdered ginger is more concentrated in flavor than fresh ginger. It's best to adjust to taste, as the strength can vary by brand and freshness.
Sources vary. One source says 1 tbsp fresh equals 1/4 tsp ground, another says 1 tbsp fresh equals 1/8 tsp ground (half as much!). So I translate them to either 1/12 tsp of ground or even less (because there are three teaspoons in a tablespoon). How about a few shakes from the jar? That's what I do when the recipe says one teaspoon freshly ground and it hasn't ruined anything yet.
As a general guideline, you can use 1/4 teaspoon of dried ginger for every 1 tablespoon of fresh ginger in a recipe. Adjust to taste based on your preference for ginger flavor.