Oil is pure fat
One cup of vegetable oil weighs about 218 g, and nearly all of that weight is fat.
Kitchen conversions, done properly
Oil to Butter Converter
A precise kitchen reference for swapping oil and butter without copying a ratio that changes the bake.
Oil to butter converter
Use
273 g
Which is also
- 1¼ cups
- 19½ tbsp
- 2⅜ sticks
- Butter is about 80% fat, so you need more of it by weight to carry the same fat as oil.
- About 80% fat, 16-17% water and milk solids. The water is why butter and oil are not a straight swap.
Show the maths
| Formula | 218 g × 1 fat ÷ 0.8 fat = 272.5 g |
|---|---|
| Source | 218 g · 218 g fat |
| Result | 272.5 g · 218 g fat |
| Ratio | ×1.25 |
To swap oil for butter, multiply the oil by 1.25 — so 1 cup of oil becomes about 1¼ cups of butter. Going the other way, multiply butter by 0.75. Those are the rules of thumb, and they are fine for most bakes. If you want the number that actually balances the fat, use Exact mode below: butter is only 80% fat, so 1 cup of oil (218 g) needs 272.5 g of butter, usually weighed as 273 g, not the 1⅓ cups you will find quoted elsewhere.
272.5 g fat-matched butter for 1 cup vegetable oil
The numbers at a glance
Oil to butter conversion chart
The amounts people ask for most, worked out both ways. Quick rule is the ratio recipes quote; Exact is fat-matched to the gram.
| Oil | Quick rule | Exact fat match | Butter grams |
|---|---|---|---|
| ⅛ cup | ⅛ cup | ⅛ cup | 34.06 g |
| ¼ cup | ⅓ cup | ⅓ cup | 68.13 g |
| ⅓ cup | ⅜ cup | ⅜ cup | 90.74 g |
| ½ cup | ⅝ cup | ⅝ cup | 136.25 g |
| ⅔ cup | ⅞ cup | ¾ cup | 181.76 g |
| ¾ cup | 0.94 cups | ⅞ cup | 204.38 g |
| 1 cup | 1¼ cups | 1¼ cups | 272.5 g |
| 1½ cups | 1⅞ cups | 1¾ cups | 408.75 g |
| 2 cups | 2½ cups | 2⅜ cups | 545 g |
Why the answer is not always obvious
How the oil to butter conversion works
Two numbers explain everything on this page: butter is about 80% fat, and oil is 100% fat. The rest is arithmetic.
Butter is about 80% fat
Butter also carries water and milk solids, so matching the fat needs more butter by weight.
Exact means transparent
The converter shows source grams, fat grams, target grams, and the ratio applied.
A better answer than copied ratios
Why 1.25 and 1.33 are both quoted — and which one is right
Search this topic and you will find two different answers. Here is where they come from, and why one of them does not survive a second look.
Common quick rule 1.25× Easy to remember
vs
Copied 1.333 rule 1.333× 1 ÷ 0.75, not fat-matched
Use the right tool for the bake
Oil to butter by recipe type
The ratio is the same everywhere. What changes is whether swapping is a good idea at all — and that depends entirely on what you are making.
Build your substitution confidence
Oil to butter by type of oil
Vegetable, olive and coconut oil do not behave identically. Coconut oil in particular is a special case.
01
Vegetable oil
The everyday swap, with quick and fat-matched answers.
02Olive oil
What changes when the oil brings its own flavour.
03Coconut oil
The solid-at-room-temperature exception explained.
04Butter to oil
Work backwards when a recipe starts with butter.
05Grams
A weight-first route for scales and precision baking.
06Ratios
The 1.25 and 0.75 rules, with the maths behind them.
The trade-offs behind the swap
Oil vs butter: texture, flavour and nutrition
Swapping fat changes more than the fat. Here is what actually shifts in the finished bake.
Texture
Oil keeps a bake soft and moist because it stays liquid when cool. Butter firms up, contributes milk solids and can add a more delicate, structured crumb.
Flavour
Neutral oil mostly disappears. Butter adds dairy richness, while olive and coconut oil can bring their own distinct notes to the finished recipe.
Nutrition
Both are energy-dense fats, but their fatty-acid profiles differ. A conversion preserves cooking proportions; it does not make a nutritional equivalent.
Straight answers, with the working shown
Frequently asked questions
How much butter equals 1 cup of oil?
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.
What is the oil to butter ratio?
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.
Why do some sites say 1.33 instead of 1.25?
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.
Can I substitute oil for butter in baking?
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.
How much oil replaces 100 g of butter?
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.
Should I use melted butter or oil?
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.
Does coconut oil convert the same way?
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.
Do I need to adjust the liquid when swapping?
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.
Is oil or butter healthier in baking?
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.
How do I convert 60 ml of oil to butter?
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.
Precision when it matters
Stop guessing at the substitution.
Use the calculator for the amount in front of you, then see exactly how the result was built.