liquid
Fish sauce
6 g1 teaspoon
18 g1 tablespoon
Fish sauce density about 1.2 g/ml; 4.93 ml tsp gives about 6 g.
Instead of Fish sauce
Nothing truly replaces fish sauce's salty, fermented fish umami; soy sauce is only a rough savoury stand-in.
Soy sauceUse about 70–80% of the weight and add a pinch of salt; it gives salt and umami but no fish funk and is darker.
Worcestershire sauceUse the same weight; it has a little anchovy depth but is sweeter, thinner and less salty.
Lime juiceFor 10 g fish sauce use about 5 g lime juice, 1 g salt and 4 g water; it gives salt and sourness but no savoury fish depth.
