Butter vs Oil in Baking

Updated September 2026 · Baking Resources

The whole butter vs oil in baking question comes down to one difference: butter is about 80 percent fat and 16 to 18 percent water, while oil is 100 percent fat and liquid at every temperature. Butter gives you flavor, browning, and lift from creaming or steam. Oil gives you a softer, moister crumb that stays soft for days, and nothing else.

Because of that fat gap, they are not a one for one swap. Replacing 1 cup of butter with 1 cup of oil hands your batter 25 percent more fat than the recipe wanted, and removes about 2 tablespoons of liquid at the same time. The result is greasy and often dry, which feels contradictory until you see the math.

Our free butter converter handles the sticks, cups, tablespoons and grams so you can get the fat number right before you swap anything.

Updated September 2026

Butter vs oil in baking: the side by side comparison

Two lines in that table do most of the work. The water line explains lift, since only butter can make steam. The melting point line explains texture, since butter is solid at the temperatures where you mix and shape, and oil never is.

Why oil cakes stay moist longer

This is the thing oil genuinely does better, and the reason a bakery carrot cake or a boxed chocolate cake almost always uses oil.

Butter is solid below about 90°F. When a butter cake cools to room temperature, the fat in the crumb solidifies, and solid fat reads as firm and dry on the tongue. Oil is liquid at room temperature and stays liquid in the fridge, so an oil cake reads as moist from the first bite to the last.

There's a second reason. Oil coats flour proteins more completely than solid butter does, which limits gluten development and slows the starch recrystallization that makes baked goods go stale. That's the same retrogradation process covered in how to store baked goods, and oil pushes back on it.

The trade you accept: you lose the butter flavor entirely, and you lose the fine even crumb that creaming produces. An oil cake is soft and slightly dense. A butter cake is lighter and tastes like something.

The conversion math: butter to oil

Match the fat first, then put the water back. Skipping the fat step makes the bake greasy. Skipping the water step makes it dry. Most failed swaps skip one or the other.

The formula:

• Oil (grams) = butter (grams) x 0.80
• Extra liquid to add (grams) = butter (grams) x 0.16

The extra liquid can be milk, buttermilk, water or whatever the recipe already uses. Milk is closest, since butter's water comes with a little milk sugar and protein along for the ride.

Worked example: turning a butter muffin recipe into an oil one

A muffin recipe calls for 1 cup of melted butter and you want to use oil so the muffins stay soft through midweek.

1. Convert the butter to grams. 1 cup = 227 g.
2. Find the fat. 227 x 0.80 = 182 g of fat.
3. Convert to oil volume. Vegetable oil weighs 218 g per cup, so 182 ÷ 218 = 0.83 cups. That's 3/4 cup plus 1 tablespoon.
4. Replace the water. 227 x 0.16 = 36 g, which is about 2 tablespoons of extra milk.
5. Expect the difference. Softer, moister muffins that keep two days longer, with no butter flavor. Since you were melting the butter anyway, no creaming was lost.

That last point matters. The swap is nearly free when the recipe melts the butter, and costly when the recipe creams it. If step one of the recipe is "beat softened butter and sugar until light and fluffy," the butter is providing structure, and oil cannot do that job at all.

The conversion math: oil to butter

Going the other way, you need more butter than you had oil, and you need to take liquid out.

The formula:

• Butter (grams) = oil (grams) ÷ 0.80
• Liquid to remove (grams) = oil (grams) x 0.20

Worked example: an oil brownie recipe made with butter

A brownie recipe calls for 1/2 cup of vegetable oil and you'd rather have the butter flavor.

1. Oil in grams: 1/2 cup x 218 = 109 g, all of it fat.
2. Butter needed: 109 ÷ 0.80 = 136 g, which is 1 stick plus about 1 1/2 tablespoons.
3. Water coming along with it: 136 x 0.16 = 22 g, roughly 1 1/2 tablespoons.
4. Take that back out of the recipe's liquid, or accept a slightly cakier brownie.
5. Melt the butter, don't cream it. Brownies want no aeration. If you want more flavor still, brown the butter first (see how to brown butter), and weigh it after browning since it loses 15 to 25 percent of its weight as water.

Note the direction of the effect. Extra water in a brownie batter pushes it toward cakey rather than fudgy. If your brownies already lean cakey, why are my brownies cakey covers the other levers.

Which one to use, bake by bake

Butter cakes and layer cakes: butter. Creaming is doing structural work here, cutting air pockets into the fat that the leavening later inflates. Oil cannot hold air, so an oil version of a creamed butter cake bakes up dense and flat. How to cream butter and sugar covers what pale and fluffy really looks like.

Chocolate cake, carrot cake, red velvet: oil. These are almost always better with oil. Strong flavors from cocoa, spice or fruit mask the missing butter flavor completely, and the moisture advantage is exactly what these cakes are judged on.

Muffins and quick breads: oil, usually. The mixing method is stir-until-just-combined, so nothing is being creamed and nothing is lost. Oil versions stay soft on day three where butter versions are drying out. If dryness is your current problem, why are my muffins dry has the full checklist.

Cookies: butter, nearly always. Butter's melting point is the reason cookies spread the way they do, and its milk solids are most of the flavor. Oil cookies exist but they're cakey and soft, with none of the crisp edge. The chewy-versus-crispy levers are all butter-based, as covered in chewy vs crispy cookies.

Brownies: either, honestly. Both work. Oil gives a fudgier, glossier brownie that stays soft. Butter gives more flavor and a slightly chewier bite. Plenty of bakers use half of each.

Pie crust, biscuits, scones, puff pastry: butter only. Not a preference, a requirement. Flakiness comes from solid fat pieces staying intact until the oven, then steaming apart. Oil coats the flour evenly and produces a sandy, crumbly crust with zero layers. See how to cut butter into flour and what is lamination in pastry for why the fat has to be solid.

Frosting and buttercream: butter only. Butter is the structure. Oil never sets, so an oil frosting is a sauce.

Bread: either, and small amounts. Enriched doughs take butter or oil interchangeably at the 3 to 8 percent of flour weight most recipes use. Olive oil in a focaccia is doing a flavor job; butter in a sandwich loaf is doing a softness job.

Not all oils behave the same

The coconut oil catch is worth spelling out. Coconut oil is solid below roughly 76°F, so it behaves like butter once the bake cools, not like oil. You get some of the firmness back that you were trying to avoid. For dairy-free swaps that keep oil's softness, a neutral liquid oil or a formulated plant butter is more predictable, and dairy free baking substitutions covers the full set.

Do not use a strongly flavored oil where the flavor doesn't belong. Extra virgin olive oil in a vanilla cupcake tastes like a mistake. In an olive oil and lemon cake it's the point.

Can you use half butter and half oil?

Yes, and it's the answer more often than people realize. You get most of butter's flavor and most of oil's moisture retention.

The math is the same, just applied to half the amount. For a recipe calling for 1 cup (227 g) of butter:

• Keep 1/2 cup (113 g) of butter
• Replace the other 1/2 cup with 6 1/2 tablespoons (91 g) of oil
• Add 1 tablespoon of extra liquid to cover the water you removed

This works especially well in yellow cake, banana bread and coffee cake, where you want butter flavor but the bake needs to survive a couple of days on the counter. It works badly anywhere creaming is load-bearing, because half the butter means half the air.

Storage and shelf life differences

Baked goods made with oil stay soft longer. That's not a small effect and it's usually the real reason a bakery item is still tender on day three.

• Oil-based cakes and muffins: 3 to 4 days at room temperature, still soft.
• Butter-based cakes and muffins: best on day one, noticeably firmer by day two.
• Refrigeration hurts butter bakes more. Cold makes butter hard, so a butter cake in the fridge goes firm and waxy while an oil cake stays soft.

If you're making something ahead, that alone can decide the swap. And whichever fat you use, cool it fully before covering, since a warm bake under a lid makes condensation. How to cool a cake has the timing.

Frequently asked questions

Can I substitute oil for butter one for one?

No. Butter is only about 80 percent fat, so a cup for cup swap gives you 25 percent more fat than the recipe intended and removes roughly 2 tablespoons of water. Use 3/4 cup plus 1 tablespoon of oil for every cup of butter, and add 2 tablespoons of extra liquid. Also check whether the recipe creams the butter, because if it does, oil cannot replace it at all.

Why are oil cakes moister than butter cakes?

Oil stays liquid at room temperature while butter solidifies below about 90°F, and solid fat in the crumb reads as firm and dry. Oil also coats flour proteins more thoroughly, which limits gluten and slows the starch recrystallization that stales a cake. The trade is that you lose butter's flavor and the fine crumb that creaming builds.

Is butter or oil better for muffins?

Oil, in most cases. Muffin batter is stirred, not creamed, so nothing is lost by switching, and oil muffins stay soft two or three days where butter muffins firm up overnight. Butter is the better pick only when the butter flavor is the point, like a brown butter muffin or a streusel-topped coffee cake.

Can I use melted butter instead of oil?

Yes, and it's the closest substitute you can make. Use 1 cup plus 3 tablespoons of melted butter for every cup of oil, and reduce the recipe's other liquid by about 3 tablespoons to account for the water butter brings. The result is slightly less moist on day three but tastes considerably better.

Does olive oil work in baking?

It works well, but pick the grade to match the bake. Light or refined olive oil is nearly neutral and swaps straight in for vegetable oil. Extra virgin brings a distinct peppery, fruity flavor that suits citrus cakes, almond cakes and focaccia, and clashes badly with chocolate chip cookies or a delicate vanilla crumb. Weight per cup is 216 g against 218 g for neutral oil, close enough to ignore.

Why do my cookies spread more with butter than with oil?

Butter melts around 90 to 95°F, so butter dough starts flowing early in the bake, before the structure has set. Oil is already liquid, but it doesn't create the same collapse, since there's no solid fat holding the dough up in the first place. Oil cookies tend to be cakey and puffy rather than flat and crisp. If your butter cookies are spreading too much, why are my cookies flat works through the causes.

Can I use coconut oil instead of butter?

Yes, with one caveat: coconut oil is solid below about 76°F, so it firms up as the bake cools and the crumb tightens more than a liquid oil would. Measure it melted, and use the same 0.80 fat conversion you'd use for any oil, plus the extra liquid. Refined coconut oil is close to neutral. Unrefined carries a real coconut flavor that shows up in the finished bake.

Which is better for brownies, butter or oil?

Both are legitimate and they give different brownies. Oil makes a fudgier, glossier brownie that stays soft for days. Butter makes a chewier brownie with more flavor and a slightly better crust on top. A half-and-half split is common and gives you most of each. Neither one should be creamed, since aeration is what makes a brownie cakey.

Related guides: What does butter do in baking | How to soften butter | Dairy free baking substitutions | Chewy vs crispy cookies | Butter converter