You reach for the butter when cooking, just like you’ve done so many times before. You’re out of butter or you want healthier less saturated fat use a mild flavored vegetable oil like Canola. Follow this chart
1 tsp. butter ¾ tsp. oil
1 tbsp. butter 2 ¼ tsp. oil
2 tbsp. butter 1½ tbsp. oil
¼ cup butter 3 tbsp. oil
⅓ cup butter ¼ cup oil
½ cup butter ¼ cup plus 2 tbsp. oil
⅔ cup butter ½ cup oil
¾ cup butter ½ cup plus 1 tbsp. oil
1 cup butter ¾ cup oil