Raw vs cooked weight calculator
Grains soak up water and get two to four times heavier when boiled; meat gives water back and loses from a fifth to two fifths of its weight. The calculator converts raw weight to cooked weight and back and shows the calories in your amount as a range, because the exact figure depends on the method and the cooking time.
Cooking does not change the calories, only the weight. That is why 100 g of dry buckwheat is 308 kcal in our calorie table, while 100 g of the cooked porridge is 77 to 147 kcal: the same calories are spread over more mass. Mixing up dry and cooked weight is one of the most common errors in a food diary.
The factors come from two sources. The first is the kitchen yield norms in order no. 818 of Russia’s Federal Penitentiary Service (24 September 2019): meat and fish, vegetables, grains. The second is the USDA table of cooking yields for meat and the energy of raw and cooked foods in USDA FoodData Central. The ends of each range are the lowest and the highest value among those sources.
How it works
- Choose the food and the cooking method.
- Say what is on the scale — raw or cooked food — and enter the weight.
- Use the range, and check it once in your own kitchen by weighing the food before and after cooking.
Why a range and not a single number
The yield norms give two figures for every grain: crumbly porridge and sticky porridge. From 100 g of buckwheat you get 210 g of crumbly or 400 g of sticky porridge — nearly twice the difference from the same grain. For meat, the spread comes from how well done it is and how thick the cut is: grilled beef tenderloin yields 80% on average in the USDA table, and 71–86% across individual samples.
Weights are for peeled foods and boneless meat, and the dishes are without oil, breading or sauce. If you added cooking oil, add its calories to the result separately.
| Food and method | Cooked weight per raw weight, and the basis |
|---|---|
| Buckwheat groats — boiled | × 2.1–4. FSIN order no. 818, annex 5: 210 g of crumbly porridge or 400 g of sticky porridge from 100 g of groats. USDA: roasted buckwheat, 346 kcal dry and 92 kcal cooked per 100 g, a factor of 3.8. |
| White rice — boiled | × 2.8–4.5. FSIN order no. 818, annex 5: 280 g of loose rice or 450 g of sticky porridge from 100 g of grain. USDA: long-grain white rice, 365 kcal dry and 130 kcal cooked, a factor of 2.8. |
| Millet — boiled | × 2.5–4. FSIN order no. 818, annex 5: 250 g of crumbly or 400 g of sticky millet porridge from 100 g of grain. |
| Pearl barley — boiled | × 3–4.5. FSIN order no. 818, annex 5: 300 g of crumbly or 450 g of sticky pearl barley porridge from 100 g of grain. |
| Durum pasta — boiled | × 2.35–3.5. FSIN order no. 818, annex 5: 250 g drained or 350 g undrained from 100 g of dry pasta. USDA: 371 kcal dry and 158 kcal cooked per 100 g, a factor of 2.35. |
| Rolled oats — cooked in water | × 4–5.3. FSIN order no. 818, annex 5: 400 g of sticky oat porridge from 100 g of grain. USDA: rolled oats, 379 kcal dry and 71 kcal cooked in water, a factor of 5.3. |
| Lentils — boiled | × ≈ 3. USDA: lentils, 352 kcal dry (as in this site’s calorie table) and 116 kcal boiled per 100 g (entry 172421), a factor of 3.0. One source, so no range: variety and cooking time shift the figure. |
| Beef tenderloin — boiled or stewed | × 0.6–0.62. FSIN order no. 818, annex 3: 74 g of raw beef (grade 1) gives 46 g boiled or 44 g stewed. |
| Beef tenderloin — fried, roasted or grilled | × 0.64–0.8. FSIN order no. 818, annex 3: 74 g of raw beef gives 47–48 g fried. USDA: grilled tenderloin 80% (71–86% across samples), top round 72% (62–83%). |
| Pork leg — boiled or stewed | × 0.61–0.67. FSIN order no. 818, annex 3: 86 g of raw lean pork gives 52 g boiled or 58 g stewed. |
| Pork leg — fried, roasted or grilled | × 0.67–0.8. FSIN order no. 818, annex 3: 86 g of raw lean pork gives 58 g fried. USDA: pork tenderloin roasted, 80% (74–84% across samples). |
| Chicken breast — boiled or stewed | × 0.76–0.77. USDA, skinless boneless breast: 120 kcal raw and 157 kcal braised per 100 g, 76%. USDA cooking yields: breast, simmered, 77% (70–88% across samples). |
| Chicken breast — fried, roasted or grilled | × 0.72–0.79. USDA, skinless boneless breast: 120 kcal raw and 151 kcal grilled per 100 g, 79%. USDA cooking yields: breast, roasted, 72% (61–82% across samples). |
| Pollock fillet — boiled or steamed | × 0.8–0.82. FSIN order no. 818, annex 3: 50 g of raw skin-on fillet gives 40 g boiled or poached; 95 g of raw loin gives 78 g. |
| Potato — boiled, peeled | × ≈ 1. FSIN order no. 818, annex 4: the weight of peeled potato does not change in boiling (80 g raw gives 80 g boiled). One source, so no range. |
| Carrot — boiled | × 0.93–1. FSIN order no. 818, annex 4: whole peeled carrot loses no weight; cut into pieces, 74 g from 80 g (92.5%). |
| Beetroot — boiled | × 0.93–0.95. FSIN order no. 818, annex 4: whole peeled beetroot, 76 g from 80 g (95%); cut up, 74 g from 80 g (92.5%). |
| Pumpkin — boiled | × ≈ 0.83. FSIN order no. 818, annex 4: 70 g of peeled pumpkin gives 58 g boiled or poached (83%). One source, so no range. |
Frequently asked questions
- How much do 100 g of dry buckwheat weigh after cooking?
- Between 210 and 400 g: 100 g of groats gives 210 g of crumbly porridge or 400 g of sticky porridge (Russian FSIN order no. 818, annex 5). The calories do not change.
- How do I count calories if I only weighed the cooked meat?
- Convert the cooked weight back to raw as a range and count the calories from the raw weight. For 100 g of fried or roasted beef tenderloin, the raw weight was 125 to 157 g.
- Why does cooked buckwheat have fewer calories per 100 g than dry?
- Water adds weight but no calories, so the same calories are spread over more mass. 100 g of dry buckwheat is 308 kcal; 100 g of the cooked porridge is 77 to 147 kcal.
Further reading
More calculators: Sugar calculator: how much a day, Alcohol calorie calculator, Calorie calculator, TDEE calculator.
This calculator gives an estimate for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.