Fish Sauce Converter

Why fish sauce needs its own density, not water's

Most cooking liquids are close enough to water's density that a straight volume conversion (mL to cups, tablespoons and back) is all you need. Fish sauce breaks that assumption. It's a concentrated, salty liquid made by fermenting fish (usually anchovies) with salt over several months, and the dissolved salt and fish protein it carries make it meaningfully denser than water — around 1.24 grams per milliliter rather than water's 1.00 g/mL. That's roughly a 24% difference, enough that weighing fish sauce as if it were water would leave you under by several grams on anything more than a teaspoon.

This converter uses grams = milliliters × 1.24 as its working formula. It's a reliable average across major brands, though the exact figure can drift by roughly ±3–5% depending on a bottle's specific salt concentration and fermentation length — fish sauce doesn't vary nearly as much as an ingredient like palm sugar, but it's still worth treating the result as a close estimate rather than a certified lab figure. If a recipe already lists fish sauce in milliliters or teaspoons/tablespoons, there's no need to convert to weight at all; this tool is most useful when a recipe (or a scale-based method) calls for it in grams and your kitchen only has measuring spoons, or the other way around.

Fish sauce is one of the most consistent Thai pantry ingredients to convert — unlike palm sugar or tamarind, its density doesn't swing wildly between brands or preparation styles, so you can trust this figure without much hedging.

Where fish sauce shows up in Thai cooking

• Tom Yum — fish sauce is one of the core seasonings balancing the soup's sour, hot and salty notes alongside lime juice and chilies.
• Pad Kra Pao (Basil Chicken) — the stir-fry sauce is built on fish sauce with garlic, chili and soy, tossed with holy basil at the end.
• Som Tam (Green Papaya Salad) — fish sauce is pounded into the dressing with lime, palm sugar and chili in the mortar.

Use the converter above to match whatever unit your recipe or a scale-based method calls for.

Frequently asked questions

Why is fish sauce heavier than water by volume?

Fish sauce carries a lot of dissolved salt and fermented fish protein, which makes it denser than plain water. Its density works out to roughly 1.24 g/mL versus water's 1.00 g/mL, so a tablespoon (15 mL) of fish sauce weighs about 18 g rather than the 15 g a tablespoon of water would weigh.

Does the brand of fish sauce change the weight?

A little. Salt concentration and fermentation length vary by brand, which can shift density by roughly plus or minus 3-5%. The 1.24 g/mL figure used here is a reliable working average for converting recipe amounts, not a lab-certified constant for every bottle.

My recipe lists fish sauce in tablespoons, how do I weigh it instead?

1 tablespoon (15 mL) of fish sauce weighs about 18 grams, and 1 teaspoon (5 mL) weighs about 6 grams. Enter your recipe's amount into the converter above to get an exact figure for any quantity.