One tablespoon of buttermilk weighs 15.3 g (poured, USDA). Buttermilk is cultured milk with a tangy flavour and a pourable consistency, and its tablespoon weight is almost identical to plain yogurt's — both are fermented milks, and both weigh a little more than plain milk because of the cultures and the slightly thicker body. The figure matters most in baking, where buttermilk is usually measured in cups, but the tablespoon weight is what you need when you are making a small batch, adjusting a recipe, or working out how much acid you are adding to activate baking soda. All weights on this page are approximate; buttermilk varies slightly by brand, so verify with a scale when it matters.
How much does 1 tablespoon of buttermilk weigh?
One level tablespoon of buttermilk weighs 15.3 g, poured, according to USDA. That is the headline number, but a single tablespoon is rarely the whole story — most recipes use several spoonfuls, or a fraction of a cup, so the table below gives the weights you will actually reach for, from a teaspoon up to a full cup. Every figure is derived from the same source value of 245 g per cup, so the whole table is consistent. Treat all of these as approximate: poured is a technique, not a machine setting, and two cooks measuring the same ingredient can differ by a gram or two per spoonful. When the recipe matters, weigh the ingredient on a kitchen scale instead.
| Amount | Weight (approx.) |
| --- | --- |
| 1 teaspoon | 5.1 g |
| 1 tablespoon | 15.3 g |
| 2 tablespoons | 30.6 g |
| 3 tablespoons | 45.9 g |
| 1/4 cup (4 tbsp) | 61.2 g |
| 1/2 cup (8 tbsp) | 122.5 g |
| 3/4 cup (12 tbsp) | 183.8 g |
| 1 cup (16 tbsp) | 245 g |
A useful rule of thumb: there are 3 teaspoons in a tablespoon and 16 tablespoons in a cup, so you can move between any of these measures by multiplying or dividing. If a recipe calls for 2 teaspoons and you only have a tablespoon measure, that is two-thirds of a tablespoon — about 10.2 g. If a recipe calls for a quarter cup and you only have a tablespoon, that is 4 level tablespoons. Keep the tablespoons to grams converter open while you cook and you will never need to do the arithmetic in your head.
Worked examples
A small batch of buttermilk biscuits
A biscuit recipe for two uses 6 tablespoons of buttermilk to bring together 1 cup of flour and a tablespoon of butter — about 92 g. The weight matters because biscuit dough is famously sensitive to liquid: too much buttermilk and the dough turns sticky and the biscuits spread; too little and the dough never comes together and the biscuits are dry. Weighing 92 g is exact, and it also tells you how much acid is in the dough — the buttermilk's acidity reacts with the baking soda in the recipe, and that reaction is what gives the biscuits their lift. A tablespoon too many throws the acid balance off and can leave a soapy taste.
Buttermilk fried chicken for four
A fried chicken marinade uses 2 cups of buttermilk — 32 tablespoons, or about 490 g — to soak four chicken pieces overnight. The tablespoon weight is useful when you only have part of a carton left and need to know whether it is enough: a carton with 200 g left holds about 13 tablespoons, which is not enough for the full marinade but plenty for two pieces. The buttermilk's lactic acid tenderises the chicken gently while its thickness helps the flour coating cling, which is why buttermilk fried chicken has a craggier, crunchier crust than chicken marinated in plain milk.
A buttermilk ranch dressing
A ranch dressing for a salad bar uses 4 tablespoons of buttermilk whisked with mayonnaise, sour cream and herbs — about 61 g. The buttermilk is what makes ranch taste like ranch: its tang cuts through the richness of the mayonnaise, and its thinness gives the dressing a pourable consistency. Weighing 61 g lets you adjust the dressing precisely — add a tablespoon more and the dressing thins and sharpens; a tablespoon less and it stays thick and mild. If you make this dressing regularly, weighing the buttermilk is what keeps it tasting the same every time.
How to measure a tablespoon of buttermilk correctly
Buttermilk is measured poured, because it is a liquid that flows freely from a jug. Pour it into a tablespoon measure and let it settle to the brim, or weigh it directly into the bowl — the second method is better for baking, because buttermilk clings to measuring jugs and you lose a few grams to the sides. The USDA figure of 15.3 g per tablespoon assumes cultured buttermilk at fridge temperature. Do not confuse cultured buttermilk with the liquid left over from churning butter, which is thinner and rarely sold; the cultured kind is what every recipe means. If you have no buttermilk, the standard substitute is 1 tablespoon of lemon juice or white vinegar per cup of milk, rested for 5 minutes — that gives you soured milk with a similar acidity, though it weighs slightly less per tablespoon and lacks buttermilk's body. For a recipe that needs only a few tablespoons of buttermilk, making a small batch of soured milk is more practical than opening a whole carton.
When the weight matters most
Buttermilk's tablespoon weight matters most because of its acidity. Buttermilk is the acid partner in countless baking recipes: its lactic acid reacts with baking soda to release carbon dioxide, which is what lifts pancakes, biscuits and soda bread. The amount of acid has to match the amount of soda — too little buttermilk and the soda is left unreacted, tasting soapy; too much and the batter turns overly tangy and can collapse. The tablespoon weight is the bridge between the recipe's cup measure and the chemistry: a recipe calling for 1 cup of buttermilk and 1 teaspoon of baking soda is balanced at about 245 g of acid against 4.8 g of soda, and knowing the per-tablespoon weight lets you scale that balance to any batch size. In savoury cooking the weight matters for marinades, where buttermilk's thickness helps coatings cling and its acid tenderises meat without toughening it the way vinegar can.
Common mistakes to avoid
The biggest mistake is using plain milk in place of buttermilk in a recipe that relies on baking soda. Without the acid, the soda never activates properly, the bake comes out flat, and the unreacted soda leaves a soapy, metallic taste. Always add an acid — lemon juice or vinegar — if you substitute. The second mistake is shaking the carton and pouring buttermilk that has separated; give it a good shake first, because the thicker cultured part settles at the bottom. The third mistake is measuring buttermilk by the cup in a dry measuring cup rather than a liquid jug or a scale, which is inaccurate for any liquid. Finally, do not throw away leftover buttermilk — it freezes well in tablespoon portions in an ice cube tray, and a frozen tablespoon weighs the same 15.3 g once thawed.
A note on the published figures
USDA lists cultured buttermilk at about 245 g per cup; King Arthur rounds it to 227 g. The figure used on this page — 245 g per cup, 15.3 g per tablespoon — is the USDA value, and it is the one the site's converters use, so the numbers here and the numbers in the tool always agree. If another source gives you a different figure, the difference is almost always the measuring method, not an error: a scooped cup weighs more than a spooned cup, and a packed spoonful weighs more than a level one.
Frequently asked questions
How many grams is 1 tablespoon of buttermilk?
One tablespoon of buttermilk weighs 15.3 g, poured, according to the USDA. One teaspoon weighs 5.1 g. These are approximate weights — brands vary slightly, so weigh it on a kitchen scale for the most accurate result.
How many tablespoons of buttermilk are in 100 g?
There are about 6.5 tablespoons in 100 g of buttermilk (100 divided by 15.3 is 6.5). A standard 500 ml carton holds about 490 g, which is roughly 32 tablespoons or 2 cups.
What can I use instead of buttermilk?
Mix 1 tablespoon of lemon juice or white vinegar into 1 cup of milk and rest it for 5 minutes. Plain yogurt thinned with a little water also works 1:1. Do not use plain milk on its own in a recipe that relies on baking soda — without acid, the soda will not activate and the bake will taste soapy.
Can I freeze buttermilk?
Yes. Freeze it in tablespoon portions in an ice cube tray, then transfer the cubes to a bag. Thaw in the fridge and shake well before using. Frozen buttermilk works perfectly in baking, though its texture is not ideal for drinking.
How long does buttermilk last once opened?
About 2 weeks in the fridge, sealed tightly. Buttermilk is already cultured, so a tangy smell is normal — discard it only if it smells sharply off, tastes bitter, or shows mould.
Related conversions
If you cook with this ingredient regularly, these pages will help: the tablespoons to grams converter for any amount, the cups to grams converter for larger quantities, and the full ingredient guide for storage, substitutes and the weight of a whole cup. You can also compare the cup weight on the Buttermilk cups to grams page or work backwards from a gram amount on the Buttermilk grams to cups page.
You may also want Yogurt tbsp to grams, Buttermilk ingredients, Buttermilk cups to grams and Buttermilk grams to cups.