A calorie calculator gives you one number. A food label gives you another. Protein guides quote different reference figures. Working out what your body needs each day starts with knowing what those numbers mean.
For generally healthy adults, daily nutrition includes energy, protein, carbohydrate, fat, fibre, fluids and vitamins and minerals. Some amounts need an individual estimate. Others are better checked by looking at the foods missing from your usual meals.
This guide focuses on adult nutrition. Pregnancy, breastfeeding, medical conditions and specialist sporting needs call for more individual advice.
Which daily numbers are worth tracking?
| Number | What it tells you | What it leaves out |
|---|---|---|
| A population reference | Guidance for a defined group | Your exact requirement |
| A calorie equation estimate | Estimated daily energy expenditure | A direct measurement of your metabolism |
| A food or recipe total | Estimated nutrients in the amount eaten | Whether your whole diet meets your needs |
Keep the source beside any target you save. A note saying “protein: 56 g” loses the reference that explains where the figure came from.
How many calories does your body need?
The FDA explains that 2,000 calories a day is a general guide on Nutrition Facts labels. Your needs can be higher or lower, depending on factors including age, body size and activity.
Our free TDEE Calculator estimates maintenance energy from your age, height, weight and activity level. It accepts ages 19 to 78 and supports metric or imperial measurements. The result estimates energy expenditure; it does not measure your metabolism or automatically prescribe a weight-loss intake.
Choose an activity description that reflects your usual week. Record why you chose it. A mostly seated working day and an active job can create different routines even when both people exercise. That note makes the estimate easier to review when your routine changes.
How much protein do you need each day?
If a clinician or dietitian has given you a target, keep that target and its reason when using the comparison below.
Protein advice needs its reference attached. US and UK readers will encounter different figures, including two distinct US frameworks.
The UK adult Reference Nutrient Intake (RNI) is 0.75 g per kilogram of body weight per day. This comes from the government’s Dietary Reference Values report; Mersey Care NHS guidance also explains the figure.
The established US Dietary Reference Intake Recommended Dietary Allowance (RDA) for healthy adults is 0.8 g/kg/day, described by the NIH Office of Dietary Supplements.
The Dietary Guidelines for Americans, 2025 to 2030, published in January 2026, gives a protein target of 1.2 to 1.6 g/kg/day in its official guidance. This is a dietary guidance target, separate from the DRI RDA.
For an illustrative adult weighing 70 kg:
| Reference framework | Calculation | Daily figure |
|---|---|---|
| UK adult RNI | 70 × 0.75 | 52.5 g |
| US DRI RDA | 70 × 0.8 | 56 g |
| US 2025 to 2030 dietary guidance target | 70 × 1.2 to 70 × 1.6 | 84 to 112 g |
Do not average these figures or assume the largest is automatically your personal target. Ask a qualified dietitian or clinician which guidance fits your circumstances if you need an individual recommendation.
Food weight and protein weight are different
A 150 g portion of chicken, beans or yoghurt does not contain 150 g of protein. Check the nutrient amount in the portion you eat. On a packaged food, check whether the label gives values per serving or per 100 g, and adjust for your portion.
Check fibre alongside protein
The UK adult fibre recommendation is 30 g a day. That is a UK guideline, not a universal figure for every age and country.
Look through a day’s meals for sources such as oats, beans, lentils, vegetables, fruit, nuts and seeds. A day can meet a protein target and still contain little of these foods. Use your portions when checking fibre totals; a cereal label may be a closer match than a generic database entry with a similar name.
How much fluid should you drink?
The NHS uses 6 to 8 cups or glasses of fluid a day as a guide. Water, lower-fat milk, tea and coffee can count. Some fluid also comes from food.
Glasses vary in size, so this is not an exact volume prescription. Heat, prolonged activity, illness, pregnancy or breastfeeding can increase fluid needs. If you keep a record, include drinks across the day instead of counting only bottles of water. Follow individual advice if you have been told to restrict fluids.
Carbohydrate, fat and micronutrients still matter
The NHS Eatwell Guide includes starchy foods, fruit and vegetables, protein foods, dairy or alternatives, and small amounts of unsaturated oils. Its balance applies across a day or week; every plate does not need to look identical.
Check what repeatedly disappears from your meals. Lunch might have protein but few vegetables. An alternative milk might be assumed to supply nutrients its label does not list. Read the product information.
Meeting calorie and macro targets cannot confirm your vitamin and mineral status. A food record can reveal omissions and help you prepare questions for a professional. It cannot diagnose a deficiency.
See what your own meals contribute
Our free Recipe Nutrition Calculator estimates nutrients from ingredient weights and USDA food entries. Include oils, sauces and toppings. Check each match against what you weighed, including whether the food was raw or cooked.
Suppose the selected entries give a batch total of 1,800 kcal and 90 g protein. Dividing every ingredient evenly into three servings gives:
1,800 ÷ 3 = 600 kcal per serving
90 ÷ 3 = 30 g protein per serving
These are hypothetical totals to demonstrate the arithmetic, not the nutrition of a particular recipe or a recommended meal.
Record the serving you actually eat. Equal container weights do not guarantee equal nutrients if one contains more chicken and another more rice. The recipe result describes the food; compare it with the reference or estimate you have chosen.
A daily food check you can reuse
Copy this table into your notes, or print it and fill in the last column.
| Check | Write down | My notes |
|---|---|---|
| Energy | Your maintenance estimate, date and activity assumption | ________________ |
| Protein | The reference used and why it fits your circumstances | ________________ |
| Food eaten | Actual portions, including cooking fats, drinks and extras | ________________ |
| Fibre | The guideline used and foods contributing to the total | ________________ |
| Fluids | Drinks across the day, with approximate amounts | ________________ |
| Food variety | Food groups regularly missing from your meals | ________________ |
| Questions | Anything the numbers cannot answer about your individual needs | ________________ |
Use this record to look for recurring gaps across your usual week. Take the ingredient amounts and the assumptions behind your targets with you if you seek individual nutrition advice.