How much salt should be used in dishes for the best flavor?

There's a reason so many recipes say "salt to taste": there's no single answer. Most of the time, we use close to 0.5% salt by weight (so 1kg food has 5g or 1 teaspoon of salt), but "close to" leaves plenty of wiggle room about what exactly is best.

Different people have different tastes. What's perfectly salted for one person may be oversalted or undersalted for another.

Different dishes need different ratios too. Some things are supposed to taste a bit salty, while some just need a hint to amplify other flavors. Some ingredients need more salt to balance them than others.

Sure, you can get approximate starting points, e.g. bread might be around 1% salt by weight, cookie dough might be about 0.5%, soups and stews might be something like 0.5% (with tons of variation - that's a couple random recipes). So very roughly, 1kg of food often comes with 5 grams of salt (1 teaspoon) with exceptions ranging up to 10 grams (2 teaspoons).

But your best bet is always going to be to find a good recipe for the specific dish you're making, and possibly adjust it if you know your preferences lean one way or another. Failing that, when cooking something improvised or new, or using one of the many recipes that just says "salt to taste", letting you do what suits you, trust the instincts that you've developed for your own tastes.

If you're cooking for others, with possibly varying tastes, it gets trickier. For things where salt can be added after the fact, you can use less salt and let everyone individually salt to taste. For things you can't mix after cooking, you pretty much have to compromise somewhere in the middle and hope it works for everyone.

Beyond that, if you can't decide what the right amount of salt is, don't worry about it. There's surely a range that works for you, so if two different amounts both taste good, there you are. And if you find yourself disagreeing with someone about what amount of salt results in the best flavor, stop. You probably just have different tastes from the person you're arguing with.

Here is my answer from a related question:

You can do a pretty good job seasoning your food simply by measuring its weight. From the book Ideas in Food:

Interestingly, as we have become more diligent about recording our recipes, we have noticed that our personal salt concentrations are very stable. Across the board, regardless of the recipe, we tend to season our food at a level of 0.5 percent of the weight of what we are cooking. There are a few exceptions where the level creeps up to 0.75 percent or down to 0.4 percent, but generally speaking, our palates are amazingly consistent.
_{[Emphasis is mine.]}

One practical roblem with stating an amount like in ESultanik's answer is not having the answer but casually implementing it - 0.5% would mean measuring out 5g of salt for a kg of food or 0.5g for 100g, and many kitchen scales will be difficult to use with any degree of accuracy at that level. Traditional tsp/tbsp measurements will be imprecise enough to seriously spoil or underseason a dish if followed by an inexperienced cook unless actual measuring spoons are used.

Variables to take into account: Differences in regional taste, differences in cuisine and dish (how other common seasonings balance with the salt and how much a briny/salty flavor is desired or undesirable), liquid content of the food and how the salt is distributed in it (or sprinkled on). "Balance" is especially important if other bitter seasonings/aromatics are introduced in quantity (eg in curry dishes).

Also, there are scientifically accepted recommendations by medical organizations (at time of writing, 500mg minimum and 2300mg maximum) for daily sodium intake, in which salt plays a big role but not the only role; baking soda and MSG, for example, have sodium too. Sodium intake from salt = grams of salt times 0.4 .

From my experience, the 'salt to taste' is a big obstacle to cooking tasty food. Imagine cooking a giant pot of soup (say 5000L). One would have to shovel salt in it, but how much is enough?

I use the following:

In the recipe for the bread you add 20g of salt per 1kg of flour (this is the ratio for every bread recipe I have seen). Now, flour is almost totaly dry (it has around 15% water content, but to make things simpler, let's say it has no water in it). With this you get a perfectly seasoned bread.

Let's use this in the case of potatoes. Potatoes have 75% water content (it doesn't change much, whether they are fresh, boiled,...). So, 1kg of potatoes has 250g of dry content and using the ratios from the bread recipe, this would amount to 5g of salt per 1kg of potatoes.

I think accurately measuring all of the ingridients, and especially salt, is the key to tasty food, and it also makes cooking food less stressful and a fun routine every day task, because you can mindlessly throw stuff in the pot and know that in the end you will be able enjoy the meal.

This is a trick question. There is no way to add salt and pepper to taste before you cook. I have Never found a scale that says to start with use so much S-N-P per lbs of chicken. Every recipe is different. Some take more some take less. And it depends of your taste buds. You can always add more but your SOL if you add to much. Most of the time I have to cook something 2 or 3 times in order to get it right. Slow down think about what your doing and write down exactly what your doing. Then you can go back and add or cut back as needed. Think of it as a road map to get the taste you want.