Sizing your frying oil
Deep-frying donuts safely and evenly starts with having enough oil at the right depth in your pot — too shallow and the donuts won’t float and cook evenly, too deep wastes oil and increases the risk of overflow when donuts are added.
This calculator treats your pot as a cylinder and uses the standard volume formula (Volume = π × radius² × height) to work out exactly how much oil fills it to your target depth, typically 2-3 inches for home deep-frying. It also estimates how many donuts you can fry at once by comparing the pot’s usable surface area (with headroom to avoid crowding) to the space one donut takes up while floating.
- Leave a few inches of empty space above the oil line, since oil rises when donuts are added and can bubble up.
- Frying too many donuts at once drops the oil temperature quickly, leading to greasy, unevenly cooked donuts — the fit estimate here already builds in spacing to help avoid crowding.
Provided for general kitchen planning; always follow safe deep-frying practices and never leave hot oil unattended.
Last reviewed August 2026