Oil to Butter

By the quick rule, 1 cup of oil becomes 1¼ cups of butter. Fat-matched, it is 272 g of butter: 1 cup of oil weighs 218 g and is 100% fat, and since butter is only about 80% fat you need 218 ÷ 0.80 = 272 g to carry the same fat.

Oil to butter is 1.25, and butter to oil is 0.75. In other words, use a quarter more butter than the oil the recipe called for, or a quarter less oil than the butter.

Because 1 ÷ 0.75 = 1.333. Someone inverted the butter-to-oil rule of thumb instead of working from the fat content, and the figure got copied. Butter is 80% fat, not 75%, so the fat-matched multiplier is 1.25 by volume. On 250 g the difference is roughly 30 g of fat, which is enough to change a bake.

Usually yes, and it works best in recipes where the fat is melted or poured: brownies, quick breads, muffins, oil-based cakes. It works least well where butter is creamed with sugar to trap air, because oil cannot hold those air pockets.

80 g of oil, which is about 87 ml or roughly ⅓ cup plus a tablespoon. Butter is 80% fat, so 100 g of butter carries 80 g of fat, and oil is pure fat.

Melted butter brings flavour and browns better thanks to its milk solids. Oil keeps bakes moister for longer because it stays liquid at room temperature. For fudgy brownies oil is often better; for flavour-led bakes, butter.

No, and this is the one genuine exception. Coconut oil is solid below about 24°C, so it behaves structurally like butter and swaps 1:1 by volume rather than 1.25.

If you replace butter with oil, yes. Butter is about 16% water, so a straight fat-for-fat swap removes liquid from the recipe. Adding a tablespoon of milk or water per 100 g of butter replaced brings it back into balance.

Per tablespoon they are close on calories, around 120 for oil and 100 for butter, since butter contains water. The real difference is fat type: butter is roughly 63% saturated, while olive and canola oils are mostly unsaturated. Neither is a health food in cake.

60 ml of oil weighs about 54.5 g. Fat-matched, that is 68 g of butter. By the quick rule you would use 75 ml of butter, which is about 5 tablespoons.

Yes. Oil and butter can be used together when a recipe benefits from butter flavour and the softness of a liquid oil. They are not the same ingredient: oil is essentially pure fat, while butter also contains water and milk solids, so the final ratio still matters.

Standard butter does not contain cooking oil. It is made from churned cream and contains butterfat, water and milk solids. Butter oil is a separate term for concentrated milk fat, similar to anhydrous milk fat, rather than vegetable oil mixed into butter.

No. Oil does not raise the burning point of butter's milk solids, so the butter can still brown and burn at the same temperature. Adding oil may make heat distribution easier to manage, but lower heat, clarified butter or ghee is the reliable solution.

Cooks combine them to get butter flavour while retaining some of oil's fluidity. The mixture can be useful for sauteing or finishing, but oil does not stop butter's milk solids from burning.