Exact butter to oil substitution
1/2 cup butter to oil
1/2 cup butter replaces with 3/8 cup (6 tablespoons / 90 ml / 82 g) vegetable oil under the classic baking shortcut, or 90.8 g of oil for an exact fat-weight match.
Oil to butter converter
6⅛ tbsp
- 81.8 g
- 90 ml
- ⅜ cup
- Quick rule: easy to remember and fine for most bakes. Switch to Exact for a fat-matched result.
- Neutral flavour and 100% fat. The default oil in most recipes.
Show the maths
| Formula | 120 ml × 0.75 = 90 ml |
|---|---|
| Source | 113.5 g · 90.8 g fat |
| Result | 81.75 g · 81.75 g fat |
| Ratio | ×0.7203 |
The calculation
How much oil replaces 1/2 cup butter?
Butter is roughly 80% butterfat and 16% to 17% water, whereas vegetable and canola oils are 100% pure fat. When swapping butter for oil, applying a 1:1 volume swap adds 20% more fat and removes moisture.
Moisture compensation: Butter contains ~16% water. In 1/2 cup butter, that equals roughly 18 ml (1 tablespoon plus 1 teaspoon) of water. In dense cakes or quick breads, add 1 tablespoon of milk or water to preserve batter consistency.
Equivalent measurements
1/2 cup butter in oil units
Quick answers
Frequently asked questions
How much oil replaces 1/2 cup (1 stick) of butter?
For everyday baking, use 3/8 cup (6 tablespoons / 90 ml) of vegetable oil under the quick 0.75 rule. For an exact fat match by weight, use 90.8 g (or 100 ml / 6.75 tbsp) of oil.
Can I use olive oil or melted coconut oil instead of vegetable oil?
Yes. Light olive oil or canola oil can be swapped using the exact same 3/8 cup measure. Virgin coconut oil swaps 1:1 by volume with butter (1/2 cup melted coconut oil) because it solidifies at room temperature like butter.
Do I need to add water when replacing 1 stick of butter with oil?
Because butter contains roughly 16% water and oil contains zero, replacing 1 stick of butter with oil removes about 18 ml (over 1 tbsp) of liquid. For lean yeast doughs or cakes, add 1 tbsp of milk or water.