Butter and Oil Substitute Calculator
Butter is about 81% fat and 18% water, and that water is why swapping it is not a straight exchange. Enter what your recipe calls for and get the amount that works, how much of the fat you can safely replace, and what it does to the calories.
Enter your amount and press Calculate.
Butter is not pure fat, and that is the whole problem
Butter is roughly 81% fat and 16 to 18% water. That water turns to steam in the oven and gives lift. Swap in oil or shortening and the water is gone; swap in applesauce or yogurt and you have added far more water than you took out.
Every adjustment on this page traces back to that one fact. It is also why a cup of butter is not replaced by a cup of oil — you are matching the fat, not the volume.
How much oil replaces butter
About three quarters of a cup of oil per cup of butter. Some university Extension services put it at seven eighths, which is the fat-for-fat arithmetic; the calculator uses the more forgiving three quarters and shows the range. Either way the result is moister and flatter, and it is the wrong move for anything that creams butter with sugar, and for pie crust, biscuits and shortbread.
Coconut oil is the one liquid fat that also works solid, so it creams better than the rest. Shortening is all fat and no water, which makes cookies spread less and turn out soft, with no butter flavour and no browning.
What fruit purées actually do
Applesauce, banana, yogurt and avocado replace the fat. They do not replace what fat does: coating flour proteins so the crumb stays tender, carrying flavour, and keeping the bake fresh. That is why every Extension service that covers the swap caps applesauce at half the fat.
None of them work for frying, pie crust, laminated dough or shortbread. Those depend on fat behaving like fat.
What it does to the calories
Replacing butter with applesauce cuts the fat of that portion of the recipe to almost nothing, and the calories with it. Replacing it with oil does not — oil is 100% fat against butter’s 81%, so a like-for-like swap slightly raises both. If cutting calories is the point, the purées are the ones that do it; the calculator shows the before and after for your own amount. For the daily total, see the daily calorie calculator.
Sources
USDA FoodData Central · King Arthur Baking ingredient weight chart · Utah State University Extension, ingredient substitution · NC Cooperative Extension, baking substitutions · Illinois Extension, healthy fat swaps
What the result tells you
The amount of your substitute that stands in for the butter or oil, and how much of the fat can be replaced at all. For oils that is all of it; for applesauce, banana and yogurt it is half at most.
How to use it
Use the amount given, keep the remainder as the original fat where the calculator says to, and read the note underneath — it says where this particular swap does not work. None of the purée swaps are for frying, pie crust or shortbread.
Recommendations
Oil for butter is about three quarters of a cup per cup, though sources go as high as seven eighths; the calculator uses the cautious figure. Coconut oil is the only liquid fat that also works solid, so it creams better than the rest. Applesauce and banana replace the fat but not what fat does, which is why every Extension service that covers the swap caps them at half.
Health & wellbeing
Replacing butter with applesauce cuts the fat of that portion of the recipe to almost nothing, and the calories with it. Replacing it with oil does not — oil is 100% fat against butter's 81%, so a like-for-like swap slightly raises the fat. If cutting calories is the goal, the purées are the ones that do it.
Troubleshooting
Cookies did not spread? You used a purée where the recipe creams butter and sugar — there is no fat to aerate. Bake dry by the next day? Purée swaps stale faster. Pie crust tough or greasy? Neither oil nor purée belongs there; that recipe needs solid fat.
How it’s calculated
Ratios come from the Cooperative Extension services of NC State, Utah State, Texas A&M, Illinois and Colorado State, plus King Arthur Baking's own test bakes. Where two credible sources disagree — three quarters against seven eighths of a cup of oil per cup of butter — the calculator uses the cautious one and says so. Cup weights are King Arthur's; nutrition is USDA FoodData Central. Ghee and tahini are listed in the table but excluded from the calculation, because no source outside recipe blogs gives a ratio for either.
Common questions
How much oil replaces 1 cup of butter?
About three quarters of a cup. Some university Extension services put it at seven eighths, which is the fat-for-fat arithmetic; three quarters is the more common and more forgiving figure. Either way the result is moister and flatter, because butter's water is gone and with it the steam that gave lift.
Can I use applesauce instead of oil?
Cup for cup, yes, and Extension services endorse it for quick breads, muffins and cookies. Replace no more than half the fat: applesauce takes the place of fat without doing fat's work, so a full swap gives a denser, chewier bake that goes stale faster.
How many sticks of butter is a cup?
Two. One stick is half a cup, eight tablespoons, or 113 grams.
Can I substitute butter for oil in a cake mix?
Yes, going the other way: use about a third more butter than the oil called for, melted, to account for butter's water content. Expect a richer flavour and a slightly firmer crumb.