Common cooking weights for baking

Some weight estimates for future baking...

(another nice chart, too bad it's in ounces!
http://www.kingarthurflour.com/recipe/master-weight-chart.html) 

Water: 1 cup = 236g

White flour: 1 cup = typical 125g, but can range from 120g and 140g, depending on flour scooping/sifting method and humidity.

Yeast: approx 2.25tsp = 7.1g, so 1 tsp = approx 3.156g

Salt: this runs the gamut, depending on salt type.

Table Salt: 1 tsp of Morton's Iodized Table Salt = 6.86g average
Lowest: 6.1g
Highest: 8.1g

Kosher Salt: 1 tsp of Morton's Coarse Kosher Salt = 4.766g average
Lowest: 4.2g
Highest: 5.2g

Baking Powder: 1 tsp of Clabber Girl baking powder = 4.167g
(rule of thumb: 1 tsp per 1 cup of flour)

White Sugar: 1 cup = 200.14g, 1 tbsp = 12.5g

Brown Sugar: 1 cup = 195g, 1 tbsp = 12.2g

Shortening: 1 cup = 205.5g

Butter: 1 tbsp = 14g, 1 stick = 1/4 lb (113g) 

Common baking measurements - salt

How much does a teaspoon of salt weight?

Turns out, not an easy answer! Here are the results:

1 teaspoon of Morton's Iodized Table Salt =
Lowest: 6.1g
Highest: 8.1g
Average: 6.86g

1 teaspoon of Morton's Coarse Kosher Salt =
Lowest: 4.2g
Highest: 5.2g
Average: 4.766g

How did I get these results?

I ran some tests: 3 different teaspoons (2 plastic, one metal), same scale (the myWeigh 500ZH, which has 0.1g accuracy).

Using each teaspoon, I measured out the salt, using the back of a knife to scrape off. After each weighing, I zeroed (tare) the gram scale. I tested each teaspoon at least 3 times.

Actual Test Results

Here was the range of results I got for Morton Iodized Salt (in grams)

6.5
6.9
6.1
6.7
6.5
7.3
8.1
7.2
6.7
6.6

Lowest: 6.1g
Highest: 8.1g
Average: 6.86g

Ran the same test with Morton's Kosher Salt, here's what I got:

4.8
4.7
5.2
4.9
4.9
5.4
4.5
4.2
4.3

Lowest: 4.2g
Highest: 5.2g
Average: 4.766g

What does it all mean?

1. Different salts have different weights: makes sense, because the salt crystal size is different, not to mention the salt strucure itself (i.e., is it airy or compact?)
   
2. Teaspoon measures vary...not all teaspoons are created equal. This is why measuring by weight is so much more accurate.
   
3. Measuring techniques will give you different outcomes.
4. Variation in measurement using volumetric measurement can be 10-20%, not insignificant (see #4)
5. Translating converting teaspoon measurements into meaningful bakers percentages is tricky. Especially when trying to extrapolate from such small measurements. With 10-20% variation, if you extrapolate a percentage by weight, then scale up, at a large quantity you will experience wildly different outcome.