Gather all ingredients.
Mix whole wheat flour, all-purpose flour, and salt in a large bowl. Use a wooden spoon to stir in water and oil. Mix until a soft, elastic dough forms and add more water, if needed.
Knead dough on a lightly floured surface until smooth.
Divide dough into 10 equal portions, or less if you want larger chapatis. Roll each piece into a ball and let rest for a few minutes.
Heat a lightly greased skillet over medium heat. Use a rolling pin to roll dough balls out on a lightly floured surface until very thin.
When the skillet starts to smoke, place a chapati in it. Cook until bottom has brown spots, about 30 seconds, then flip and cook 30 seconds more.
Repeat to cook remaining chapatis.
