Butter-Oil Converter 🧈
Enter the amount of butter your recipe calls for and choose a substitute oil to get the equivalent amount.
The Butter-Oil Converter swaps butter for vegetable, olive, coconut, canola, or avocado oil — useful when you've run out of butter, want a dairy-free bake, or need a moister, softer crumb. Butter is roughly 80% fat and 18% water; most cooking oils are 100% fat. A 1:1 swap by weight delivers too much fat and too little water, so the standard adjustment is 0.75 g of oil per 1 g of butter (or about ¾ cup oil per 1 cup butter). Coconut oil is the closest behaviorally because it solidifies below 24 °C and contains a small amount of water, so it uses a 0.8 ratio. Each oil also brings a different flavor signature: vegetable and canola are neutral, olive adds peppery notes, coconut adds tropical aroma, avocado is buttery with a high smoke point. Pick the oil based on the bake — pound cake suits vegetable, focaccia suits olive, dense chocolate cakes love avocado, and tropical loaf cakes shine with coconut.
How to Use the Butter-Oil Converter
- Enter Butter Amount — Enter the amount of butter your recipe calls for in grams, ounces, or cups.
- Choose Substitute Oil — Select vegetable, olive, coconut, canola, or avocado. Match flavor to recipe — neutral oils for delicate cakes, olive for savory bakes, coconut or avocado for dense rich crumbs.
- Read Oil Amount — The calculator returns the oil amount in your chosen unit. Standard 0.75 ratio for liquid oils, 0.80 for coconut oil.
- Skip Creaming, Whisk Liquids — Recipes that cream butter and sugar (cookies, pound cake) need different handling with oil. Whisk oil and sugar with eggs and liquids, then fold dry ingredients in. The crumb will be tender but not as fluffy as creamed butter.
- Adjust Liquid If Needed — Butter contributes water. Replacing 100g butter with 75g oil removes about 18g of water — for high-precision bakes (custard cakes, chiffon), add 1–2 tbsp of milk or water back to keep crumb moisture right.
Formula Reference
Oil weight = butter weight × 0.75 (vegetable, olive, canola, avocado). Coconut oil weight = butter weight × 0.80 — coconut oil contains a small amount of water and behaves more like butter. Volume conversions assume melted butter (≈0.91 g/mL) and oil density of about 0.92 g/mL: 1 cup butter (227 g) ≈ ¾ cup oil (≈170 g, ≈185 mL). Butter composition baseline: 80% fat, 18% water, 2% milk solids. Standard US sticks: 1 stick = 113 g = ½ cup = 8 tbsp.
Source: Harold McGee, On Food and Cooking, 2nd ed. (Scribner, 2004) — Fats and Oils chapter; America's Test Kitchen — Butter-to-Oil Substitution research.
FAQ
Why does the converter use a 0.75 ratio instead of 1:1?
Butter is only 80% fat, so 100g butter contains 80g of fat. Most oils are 100% fat, so 75g of oil delivers 75g of fat — a near-equivalent fat content. A 1:1 swap by weight would over-fat the recipe by 25%, leading to greasy, dense baked goods.
Can I substitute oil for butter in cookies?
Yes, but the result is different. Oil produces a denser, chewier cookie that spreads more. For chewy chocolate chip cookies, the swap works well; for shortbread or sablés that rely on creamed butter, oil compromises the texture. Use a 0.75 ratio and chill the dough for 30 minutes before baking.
Is olive oil OK in a cake?
Yes — olive oil cakes are a classic Italian and Mediterranean technique. Use mild extra-virgin olive oil for chocolate, citrus, or almond cakes; the flavor adds savory depth. Avoid robust peppery oils in delicate vanilla or sponge cakes.
How does coconut oil change a recipe?
Coconut oil is solid below 24 °C, so it can be creamed like butter when soft, or melted and treated like liquid oil. Use refined coconut oil for neutral flavor, virgin for tropical aroma. The 0.80 ratio compensates for the small water content.
Can I go the other way and replace oil with butter?
Yes. Use butter weight = oil weight × 1.33 for liquid oils (or × 1.25 for coconut). Melt the butter to mimic oil's pour behavior, and reduce the recipe's other liquid by 18% of the butter weight to compensate for the added water.
Related Tools
- Egg Substitute Calculator — Pair the oil swap with a vegan egg substitute for fully plant-based recipes.
- Baking Unit Converter — Convert butter sticks to grams or cups before applying the conversion ratio.
- Recipe Scaler — Scale a recipe to a different batch size while keeping the butter-to-oil ratio.
- Baking Cost Calculator — Compare ingredient cost when swapping butter for oil in production recipes.