Free tool: Calculate your TDEE (daily calories) and macro targets for fat loss, maintenance, or muscle gain — free.
What TDEE and macros mean
Your TDEE (Total Daily Energy Expenditure) is the number of calories you burn in a day, including everything from basic body function to exercise. It’s the single most useful number for managing your weight: eat below it to lose fat, at it to maintain, above it to gain. Macros (macronutrients) are how those calories break down into protein, carbohydrates, and fat. This calculator estimates your TDEE, adjusts it for your goal, and splits the result into daily macro targets in grams.
How it’s calculated
The tool uses the Mifflin–St Jeor equation, the most accurate widely-used formula for estimating your baseline metabolism (BMR), then multiplies by an activity factor to get TDEE. For your goal it applies a sensible adjustment — roughly a 500-calorie daily deficit for steady fat loss, or a modest surplus for lean muscle gain. The macro split shown (30% protein, 40% carbs, 30% fat) is a balanced, paleo-friendly starting point that keeps protein high to protect muscle and satisfy hunger.
Using it on a paleo diet
Paleo isn’t usually about counting every calorie, but knowing your numbers helps if you have a specific goal like fat loss or building muscle. Hit your protein target from quality meat, fish, and eggs; get carbs from fruit and starchy vegetables like sweet potato; and fill fat from avocado, nuts, olive oil, and the natural fat in your protein. You can follow the targets loosely, using them to sense-check portions rather than weighing every gram, and still benefit from the structure.
Treat it as a starting point
These are estimates. Real metabolism varies between individuals, so use the numbers for two to three weeks, track your weight trend, and adjust: if fat loss stalls, trim calories slightly; if you’re losing too fast or feel drained, eat a bit more. Activity level is the most common thing people overestimate, so be honest there. For medical conditions, pregnancy, or a history of disordered eating, work with a doctor or registered dietitian rather than a calculator.
Frequently asked questions
How is TDEE calculated?
This tool estimates your BMR with the Mifflin–St Jeor equation, then multiplies by an activity factor. Your goal target adjusts that up or down (e.g., −500 calories for fat loss).
What macros should I eat?
A balanced starting split is 30% protein, 40% carbs, 30% fat, which this tool calculates in grams. Adjust based on your goal and how you feel; keep protein high to preserve muscle.
Are these numbers exact?
No — they’re well-validated estimates. Use them for 2–3 weeks, watch your weight trend, and fine-tune. Individual metabolism varies.
General nutrition information, not medical advice. Estimates vary by individual; consult a doctor or dietitian for medical conditions, pregnancy, or personalized plans.
How accurate is the Mifflin–St Jeor equation?
It’s the most reliable of the common formulas, but it’s still an estimate. Mifflin and St Jeor built the equation in 1990 from resting energy measurements (by indirect calorimetry) in 498 healthy adults aged 19 to 78, about half of them normal weight and half with obesity. In the same study, the older Harris-Benedict equations overestimated measured resting energy expenditure by about 5% (Mifflin et al., 1990, PubMed).
A 2005 systematic review for the American Dietetic Association compared the four most-used equations and found Mifflin–St Jeor predicted resting metabolic rate within 10% of the measured value in more people, both with and without obesity, than any other equation, with the narrowest error range. The same review warned that older adults and U.S. ethnic minority groups were underrepresented in the validation studies, so errors can be larger for them (Frankenfield et al., 2005, PubMed).
In practice, that means the calculator’s BMR is usually close, but for any one person it can be off by 10% or more. The activity multiplier adds more uncertainty than the equation itself.
What do the activity levels mean, and how much do they change your number?
The calculator multiplies your BMR by one of four activity factors. Here is what each setting uses and what it does to a single example: a 40-year-old woman, 5 ft 5 in, 160 lb, whose Mifflin–St Jeor BMR works out to about 1,397 calories.
| Calculator setting | Multiplier | Example TDEE | Who it fits |
|---|---|---|---|
| Sedentary | 1.2 | 1,676 cal/day | Desk job, little planned exercise |
| Light (1–3 days) | 1.375 | 1,920 cal/day | Short workouts or long walks a few days a week |
| Moderate (3–5 days) | 1.55 | 2,165 cal/day | Regular training most days, or an on-your-feet job |
| Very active (6–7 days) | 1.725 | 2,409 cal/day | Hard daily training or physical labor |
Calculation: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161 for women (+5 for men), per Mifflin et al., 1990, multiplied by the calculator’s activity factors. Example inputs: 72.6 kg, 165.1 cm, age 40.
The gap between “sedentary” and “very active” for the same person is more than 700 calories a day. If you’re unsure, pick the lower level and adjust after a few weeks.
Worked example: turning the result into a paleo day
Take the same woman choosing Light activity and the “Lose fat (−500)” goal. The calculator returns a maintenance TDEE of 1,920 calories and a goal target of 1,420 calories, split into about 107 g protein, 142 g carbohydrate and 47 g fat.
How does that compare with official ranges and with what paleo studies used?
| Macronutrient | Calculator split | Example at 1,420 cal | Acceptable Macronutrient Distribution Range (adults) | Paleo diet arm in a 2-year Swedish trial |
|---|---|---|---|---|
| Protein | 30% | 107 g | 10–35% of calories | 30% |
| Carbohydrate | 40% | 142 g | 45–65% of calories | 30% |
| Fat | 30% | 47 g | 20–35% of calories | 40% |
Sources: AMDRs from the Institute of Medicine’s Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids; paleo trial split as summarized by the Harvard T.H. Chan School of Public Health paleo diet review.
Two things stand out. The calculator’s 40% carbohydrate sits a little below the AMDR’s 45% floor, and well above the 30% used in the paleo trial, so it’s a middle ground; if you eat plenty of fruit and sweet potatoes you’ll naturally land near it. And the protein target is generous: 107 g is about 1.5 g per kilogram of body weight, compared with the National Academy of Medicine minimum of 0.8 g per kilogram (about 58 g for this person) cited by Harvard’s Nutrition Source. Higher protein is common on paleo, but if you have kidney disease, ask your doctor before raising your intake.
In food terms, 1,420 calories with 107 g protein could be three eggs with spinach and berries at breakfast, a chicken salad with avocado at lunch, and a 5 oz piece of salmon with broccoli and a small sweet potato at dinner. Our 7-day paleo meal plan averages about 1,750 calories and 103 g protein a day, so a lower target mostly means smaller portions of nuts, oil and starch.
Why might your real results differ from the calculator?
- Metabolism varies. Even the best equation misses by 10% or more for some people.
- Activity is easy to overestimate. A one-hour workout doesn’t make a desk-bound day “very active.”
- Your needs change as your weight changes. Recalculate after every 10 lb or so of change.
- Food logging is imprecise. Oils, nuts and “a handful” of anything are the usual gaps.
For a second estimate that models how intake changes over time, try the National Institute of Diabetes and Digestive and Kidney Diseases’ Body Weight Planner, which estimates the calories needed to reach and then maintain a goal weight based on your starting information and activity. If the two tools disagree, start from the lower number and let two to three weeks of real results guide you. People who are pregnant, managing diabetes or kidney disease, or have a history of disordered eating should set targets with a doctor or registered dietitian rather than a calculator.
Research cited in this guide
We checked this guide against the nutrition and health sources below. They are worth reading for the underlying detail.