It depends on which system the recipe uses. A US customary cup is 236.588 ml (often rounded to 237), metric and Australian metric cups are both 250 ml, and a Japanese cooking cup is 200 ml. The 180 ml Japanese rice cup is a separate measure again. Imperial has no official cup at all, so a British recipe writing cup needs its own notes or measuring tool checked.

Both, depending on the system. Metric and Japanese tablespoons are 15 ml, a US customary tablespoon is 14.787 ml, and an Australian tablespoon is 20 ml — a third larger than the others, which is enough to matter in baking and in seasoning. Teaspoons vary far less, at 5 ml everywhere except US customary, which is 4.929 ml.

Do not infer it from the language the recipe is written in or from where you live, because neither reliably indicates the system. Check the recipe source or its notes, or read the markings on the measuring cup you are actually holding. If you still cannot tell, leave the system unselected and this page shows only the readings that would genuinely change your answer, side by side, instead of silently picking one for you.

Yes, for 11 ingredients, and every figure names who published it. A cup of all-purpose flour is 125 g by USDA standard reference but 120 g by King Arthur — same cup, 4% apart, because the gap is not cup size but how the flour gets into the cup. So this tool shows every published figure side by side instead of picking one for you, and it never derives a weight the source did not publish. If your recipe prints weights, those win; a kitchen scale beats any cup.