Calculate the exact substitution ratio of oil to butter for your recipes.
You will need:
1.33
Butter
Pro Tip: Butter consists of 80% fat and 20% water/milk solids, whereas oil is 100% fat. This means you generally use less oil when substituting for butter to maintain the correct fat ratio in baking.
Last updated: August 2026
The Science of Substituting Oil and Butter
Whether you've run out of butter halfway through a recipe or you're trying to make a dairy-free dessert, swapping butter for oil (or vice versa) is a common kitchen hurdle. Our Oil to Butter Conversion Calculator makes the math effortless.
Why isn't it a 1:1 conversion?
It all comes down to fat content. Butter is an emulsion of fat (about 80%) and water/milk solids (about 20%). Cooking oils, such as vegetable, canola, or olive oil, are 100% fat.
If you were to replace 1 cup of butter with 1 cup of oil, you would be adding 20% more fat to the recipe than intended, which can result in a greasy, heavy bake. By reducing the oil to 3/4 cup, you match the exact amount of fat that was in the original cup of butter.
A Worked Example
For 2 cups of butter, use 1.5 cups of oil (2 × 0.75). Going the other way, if your recipe calls for 1 cup of oil and you only have butter, use about 1.33 cups of butter (1 ÷ 0.75).
Frequently Asked Questions
Yes! You can substitute oil for butter in most recipes like muffins, quick breads, and cakes. However, since oil is 100% fat and butter is 80% fat and 20% liquid, you cannot always use a 1:1 ratio.
The standard rule is to use 3/4 cup of oil for every 1 cup of butter. This maintains the correct fat ratio in your recipe.
For baking, neutral oils like canola oil, vegetable oil, or melted coconut oil work best because they don't overpower the flavor of your baked goods.
Yes, the 3/4 ratio is based on fat content, not flavor, so it applies whether you're using canola, vegetable, or another neutral oil. Extra virgin olive oil works too, though its stronger flavor may come through more in the finished bake.
Measure the butter melted, since that's the fair comparison to liquid oil. A cup of solid butter and a cup of melted butter aren't quite the same volume.
Most sources agree closely on butter-to-oil (about 3/4 cup oil per cup of butter). The reverse direction sometimes varies a little since butter's water content can be handled differently — this calculator uses the direct mathematical inverse (divide by 0.75) so both directions stay consistent with each other.
Subtly, yes. Butter contributes a richer flavor and helps create a flakier texture, while oil tends to produce a moister, denser crumb. Most people notice little difference in muffins or quick breads, but it's more noticeable in cookies or pastries.
