CalcHive › Nutrition
Nutrition Calculators
Last updated: October 2, 2026. Maintained by CalcHive, JAE's Holding Solutions LLC.
Eight tools: maintenance calories, grams, protein per kilogram, a weekly planner, a grocery list, meal-prep portions, cost per gram of protein, and a household food-plan budget.
Estimate only, not medical advice. This does not diagnose or treat any condition or replace a doctor or registered dietitian. If you are pregnant, under 19, managing a medical condition or an eating disorder, or on a prescribed diet, get individual guidance.
This section is arithmetic you can read. Each tool tells you the equation it runs, shows worked numbers from that equation, and stops there. Nothing is an account, a saved meal plan, or a food database. The numbers stay in your browser. A link from one tool to the next only copies figures into the address bar.
Start here
- TDEE calculator. Mifflin-St Jeor resting energy, times an activity factor you pick, plus an optional calorie offset you type.
- Macro calculator. Protein, fat, and carbohydrate grams from a calorie target, or calories from grams you already have.
- Protein intake calculator. Grams at 0.8, 1.2, and 1.6 grams per kilogram, with a custom rate if you bring your own.
- Weekly meal planner. A 7-day grid of meals you type or pick. Daily and weekly sums versus targets you set. Not a recipe generator.
- Grocery list generator. Scale recipe lines and merge amounts that share a unit family. Cups and ounces of the same food stay on separate lines.
- Meal prep portion calculator. Divide a batch you describe, then split containers using the FSIS 3-to-4-day refrigerator window.
Use the first three in that order when you are starting from height and weight. Skip ahead when you already have the number the earlier page would have produced. The macro page can take a calorie total without a visit to the TDEE page. The protein page can take a weight without either of the others. The planner adds meals you already described. The grocery list and the portion calculator do not need a calorie target. They run on the recipes and batch totals you type.
Available now
How to choose
The TDEE page answers "what does this equation say my maintenance calories are?" It does not answer how many calories a walk burned, and it does not turn a deficit into pounds. The macro page answers "if this many calories, this protein rate, and this fat percent, how many grams are left for carbohydrate?" Recipe mode on that page answers "if these grams, how many calories do 4, 4, and 9 produce?" The protein page answers "what is 0.8, 1.2, and 1.6 grams per kilogram at this weight?" It does not name foods.
The weekly meal planner is the grid after you have numbers. It sums meals you type. Fill my week only reshuffles that list. It does not invent recipes. The grocery list scales and merges ingredient lines. It does not look up nutrients or store prices. The meal prep page divides a batch you already totaled and uses the FSIS 3-to-4-day refrigerator window as a fridge-versus-freezer count.
Money branch
Two tools answer money questions and do not set a calorie target. The protein cost calculator is package price divided by protein grams, both typed by you. The household grocery budget calculator sums weekly USDA food-plan costs you paste, applies the household-size percent from USDA's footnote, and multiplies the adjusted weekly total by 4.333. It does not keep a price table. The August 2026 figures on that page are an illustration, checked October 2, 2026, and the page says to open the current USDA Food Plans report before using them.
Health tools on this site answer different questions and should stay separate. BMI is weight relative to height. Body fat is the Navy tape formulas. Water intake is a half-body-weight fluid estimate, not a National Academies adequate intake. Heart-rate zones are beats per minute from age. None of those inputs replace the Mifflin equation, and the Mifflin page does not read a tape measurement. Cooking tools scale one recipe or convert a unit. The grocery list is the page that merges several recipes. If you already have grams, the macro calculator's recipe mode is the calorie check.
There is no calorie-burn calculator in this section. The eight tools above are the ones that run today. Send a request if you want to tell us which question is missing.
Guides
Two explainers use the same arithmetic as the tools on this hub. They do not add a ninth calculator.
- Your calorie estimate is a starting point. What the TDEE page's Mifflin result is for, why a different activity factor moves it, and how to change the offset you type.
- Budget high-protein meal prep. Cost per gram from prices you type, a Sunday batch inside the FSIS leftovers window, and a family-of-4 comparison with the USDA food-plan footnote.
What the calorie tools share
Pounds become kilograms by dividing by 2.20462. Inches become centimeters by multiplying by 2.54. Protein and carbohydrate use 4 kcal per gram, and fat uses 9, when a page needs energy factors. Headlines that are calorie totals round to the nearest 10 kcal and say so. Reference amounts are quoted from the page that published them, with the date we read it. Activity factors 1.2, 1.375, 1.55, 1.725, and 1.9 are labeled as a common convention. They are not given a fake official citation.
Each tool warns rather than inventing a personal minimum. The TDEE and macro pages say when an adjusted calorie target is below estimated BMR, or when nearest-10 rounding leaves it no higher than nearest-10 BMR. That warning is a display rule on those pages. It is not a coded calorie floor from a guideline. The protein page will not swap in a goal weight you did not type.
FAQ
Are these nutrition calculators medical advice?
No. They apply the formulas printed on each page to the numbers you type. They do not diagnose, prescribe a diet, or replace a doctor or a registered dietitian.
Which calculator should I open first?
If you need a calorie estimate, start with the TDEE calculator. If you already have a calorie number and want grams, open the macro calculator. If the question is grams of protein per kilogram, open the protein calculator. If you already have meals and want the week added up, open the weekly meal planner. Each page states what it does not calculate.
Do these pages store what I type?
The math runs in the browser. A link from TDEE to the macro page, or from macros to the protein page, puts numbers in the address bar so the next form can fill in. Nothing is sent to a CalcHive server. The weekly meal planner can save the grid in this browser's local storage if you use Save on this device. The other nutrition pages do not use local storage.
Where are BMI, body fat, and water intake?
On the health calculators hub. BMI is a screening index. Body fat on this site is the Navy tape method. Water intake is a half-body-weight estimate. None of those pages is a calorie or protein calculator.
Is there a calorie-burn calculator here?
There is no calorie-burn calculator on this hub. The live tools are the TDEE calculator, the macro calculator, the protein intake calculator, the weekly meal planner, the grocery list generator, the meal prep portion calculator, the protein cost calculator, and the household grocery budget calculator. The budget tool applies USDA's household-size adjustment to weekly costs you paste. It does not store a USDA price table.
Sources we rely on
Checked October 1, 2026. Each tool repeats the sources that apply to its own formula.
- Mifflin et al., 1990, PubMed 2305711. Resting-energy equations, the 19 to 78 age span, and the Harris-Benedict comparison in that paper's abstract.
- 21 CFR 101.9. General factors of 4, 4, and 9 calories per gram, and label calorie rounding.
- Dietary Guidelines for Americans, 2025–2030 (PDF). Protein serving goals of 1.2 to 1.6 g/kg/day, and the note that calories depend on age, sex, height, weight, and activity.
- National Academies DRI macronutrient table (2002/2005). Adult protein basis of 0.8 g/kg/day and the adult AMDR percent bands.
- NIDDK, on the 3,500 calorie per pound rule and the Body Weight Planner.
- FSIS leftovers and food safety. The 3-to-4-day refrigerator window used by the meal prep portion calculator.
- USDA FoodData Central. Linked from the protein cost page. Nutrient values are not copied onto CalcHive.
- USDA Food Plans monthly cost reports. Checked October 2, 2026 for the household-size footnote and the August 2026 illustration on the budget page. Those dollar tables are not stored here as a live price list.
Need a nutrition tool we do not have? Send a request. We read every one.