Calories in a Spanish omelette: slice, portion and whole
How many calories a slice, a portion and a whole Spanish omelette have, using Kalo's standard recipe, and why the number can shift by 20% with the oil.
The tortilla de patatas, or Spanish omelette, is one of the hardest dishes to size up by eye: it depends on the size, whether it has onion and, above all, how much oil it has soaked up. This is the estimate Kalo uses.
The standard recipe
Kalo works out the tortilla from a reference recipe: 500 g of potato, 300 g of egg (about 5), 120 g of onion and 70 g of olive oil. Cooked, it weighs about 850 g and has around 174 kcal per 100 g.
Calories by portion
| Portion | Weight | Approx. calories |
|---|---|---|
| Tapa | 70 g | 120 kcal |
| Slice (pincho) | 110 g | 190 kcal |
| Portion (ración) | 250 g | 440 kcal |
| Whole omelette | 850 g | 1,480 kcal |
Why it’s a range and not a single number
Two “identical” omelettes aren’t. Oil weighs heavily: it has about 884 kcal per 100 g, so an extra 20 g adds roughly 180 kcal across the whole omelette. It also changes if the potato is fried or slowly poached, whether there’s onion, and how thick the slice is.
That’s why Kalo doesn’t give you one number but a range, and lets you adjust the portion and the oil before saving. For this recipe, the variability it uses is around 20%.
How to log it
- With a photo: Kalo suggests it’s a tortilla and you choose whether it’s a slice, a portion or more.
- With text: type “a slice of tortilla” and it logs it offline and for free.
The figures are estimates from a standard recipe, not measurements of your plate. They don’t replace a health professional’s advice.