A homemade dinner rarely comes with a nutrition label. It comes with a pan, a handful of ingredients and portions that are not all the same size. You can still make a useful calorie estimate: add up what went into the food, measure the finished batch, and work out how much of that batch reached your plate.
- Use the weight and nutrition information for each ingredient in the same state: dry, raw, cooked or drained.
- Include cooking oil, sauces and toppings that make it into the meal.
- Divide the batch calories by its finished food weight, then multiply by your portion weight.
- Treat the result as an estimate; ingredient data and uneven portions still introduce uncertainty.
Jump to the portion calculator ↓
Start with the ingredients
Write down the ingredients as you add them. A short list with grams is enough: chickpeas, tomatoes, carrots, onion and oil, followed by any sauce or topping. Weigh the part going into the dish. A jar's total weight is not the weight of the food you scooped out of it.
For packaged ingredients, read the nutrition panel on the product you used. For basic ingredients without a label, choose a suitable entry in a food-composition database. Check the description as carefully as the calorie number: canned chickpeas, drained, are a different entry from dried chickpeas. The same rule applies when choosing between raw and cooked weights.
USDA FoodData Central describes its portion weights as edible material, excluding refuse. That distinction matters when a scale includes a peel, bone, shell or liquid you will discard.
Check what the label's number refers to
A label may give calories per serving, per 100 g, or for the whole package. The FDA's serving-size guide explains that a package can contain several servings; the stated serving size is not a recommendation for how much to eat.
If a sauce lists 60 kcal per 30 g and you add 45 g, the contribution is 60 × 45 ÷ 30 = 90 kcal. If a label gives a per-100-g value, multiply that value by the grams used and divide by 100. Keep the units visible while you calculate.
Milk in porridge, smoothies or sauces counts as an ingredient too. Our comparison of lower-calorie plant-based milks shows why the exact product and amount poured matter, with calories per cup and per 100 ml.
A complete worked example
Imagine a chickpea and tomato stew. The numbers below are deliberately rounded, illustrative label values to make the arithmetic easy to follow. They are not measurements of the cover image or a reference recipe. Use your own products' values when cooking.
| Ingredient and state | Added | Example kcal / 100 g | Batch kcal |
|---|---|---|---|
| Canned chickpeas, drained | 500 g | 120 | 600 |
| Chopped tomatoes, with juice | 400 g | 25 | 100 |
| Carrots, raw, trimmed | 200 g | 40 | 80 |
| Onion, raw, peeled | 100 g | 40 | 40 |
| Oil | 20 g | 900 | 180 |
| Water | 300 g | 0 | 0 |
| Total before cooking | 1,520 g | — | 1,000 |
The batch starts with an estimated 1,000 kcal. After simmering, suppose the food weighs 1,250 g. In this example, the weight difference is evaporated water. The smaller cooked weight changes calories per gram; it does not, by itself, remove calories from the recipe.
Weigh the finished food
You need the weight of the food, excluding its container. One option is to note the empty pot's weight before cooking and subtract it later. Another is to transfer the finished food into a suitable bowl on a scale that has been zeroed for that bowl.
For example, a pot plus stew weighs 2,150 g. The empty pot weighed 900 g. The batch contains 2,150 − 900 = 1,250 g of food. Use this final weight as the denominator, not the 1,520 g ingredient total.
The FAO method for calculating recipes combines ingredient nutrient totals with the final prepared yield, accounting for relevant changes during cooking. At home, the same basic distinction helps: ingredient data supplies the calorie estimate; the cooked batch supplies the portion weight.
Calculate the part on your plate
Portion calories = batch calories × portion grams ÷ finished batch grams. Use the weight of the food without its container.
From the pot to your plate.
In the whole recipe.
Include oil and everything that stays in the dish.
After cooking.
Weigh the finished food without the pot.
On your plate.
375 ÷ 1,250 = 30% of the batch.
30% of the batch
× 1,000 kcal in the recipe
A 375 g serving is 30% of the 1,250 g batch, so it receives 30% of the estimated calories. Alternatively, the stew has 80 kcal per 100 g: multiply 80 by 3.75 to reach the same result.
This works best when the mixture is reasonably even. A bowl mostly filled with broth and another full of chickpeas will not have the same calories per gram. Stir mixed dishes before portioning, or measure separate components when the meal consists of distinct pieces, sauce and sides.
Oil, sauces and what gets left behind
Include oil added to a stew, butter stirred into potatoes, cheese on top and dressing on a salad. If a topping goes only on your plate, add it to your portion rather than distributing it across everyone's meal.
A poured amount of oil is not always the amount eaten. Oil can stay in a pan, fat can drain away, and marinade can be discarded. Do not subtract an arbitrary percentage and call it precise. If the amount left behind is unknown, the calorie estimate is uncertain too.
For meat cooked separately, a database entry matching the cooked cut and preparation may be more useful than treating every gram of raw fat as eaten. The USDA cooking-yield tables distinguish moisture changes from fat gains and losses. Weight loss during cooking is not a measurement of calories lost.
Also check what a prepared-food entry already includes. Adding oil again to an entry that already describes the food cooked with oil can double-count it. Match the entry to your preparation, then add only what it does not cover.
Shared meals and leftovers
If you divide the stew into four genuinely equal portions, each gets about 250 kcal. If the portions differ in size, weighing each is more informative than entering “one serving” for all four.
Keep a short batch note: “Chickpea stew: 1,000 kcal total; 1,250 g finished.” It gives tomorrow's lunch a usable reference without repeating the ingredient arithmetic. If you portion food before storing it, each container keeps its assigned share even if reheating later changes its water weight.
If you reheat the entire batch and it loses more water, weigh the remaining food again before using grams to divide it. Added cheese, cream or oil also changes the remaining calorie total. The practical aim is a consistent method you understand, not a claim that every spoonful has been measured in a lab.
Common questions
What if I do not own a kitchen scale?
Use package amounts, measured household portions or an equal division of the batch. For example, half a carton plus one measured spoon of sauce is a better documented estimate than an unexplained “medium serving.” It will be less specific than weighing; keep that uncertainty in mind.
Should I log every ingredient and the finished meal?
Choose one accounting method for what you eat. Logging your ingredient share and then logging the meal total again counts the same food twice. A recipe note can hold the calculation while the diary receives only your portion.
Can AI calculate a homemade meal?
It can help estimate a described meal, particularly when you include amounts, cooking method and added fats. A photo alone cannot reveal the full recipe or how much oil stayed in the food. Check the proposed quantities and figures before saving; see our guide to what a photo calorie estimate can and cannot tell you.
How do I enter the result in Burnline?
Use manual logging for the calories you calculated for your portion, with a name you will recognise later. If you use AI Estimate instead, describe the serving and review its result. The diary should contain the amount you ate, not the entire pan.
Where the guidance comes from
Label and food-composition guidance underpins the method. Worked examples are original, simplified calculations; their numbers are illustrative rather than measured meal data.
