Calorie Calculator (TDEE & Macros)

HealthInstant resultsFormula shown100% in your browser

Estimate your daily calorie needs (BMR and TDEE) with the Mifflin-St Jeor equation, adjust for your goal, and get a protein, carb and fat macro split. Everything is calculated in your browser.

Inputs

Sex

Age (years)

Height (cm)

Weight (kg)

Activity level

Physical Activity Level (PAL) multiplier applied to BMR.

Goal

Macro split

Body fat (optional) (%)

If > 0, Katch-McArdle BMR is also shown (more accurate for lean athletes).

How to use this calculator: Calorie Calculator (TDEE & Macros)

Estimate your daily calorie needs (BMR and TDEE) with the Mifflin-St Jeor equation, adjust for your goal, and get a protein, carb and fat macro split. Everything is calculated in your browser. The example below is calculated by this page's real engine from the displayed inputs.

1Confirm that the Calorie Calculator (TDEE & Macros) matches the quantity or design check you need.
2Enter Age, Height, and Weight using the units printed beside each field.
3Select the applicable Sex, Activity level, and Goal options; these choices change the calculation method or factors.
4Calculate, then follow the substituted equations in the worked example and compare the result with any stated limit.
5Read the assumptions, warnings and cited references before using the result for a financial, medical or engineering decision.

Input guide and example values

Use values from the same measurement basis and time period. Conditional fields appear only when the related option is selected.

Input	Example value	Why it matters
Sex	Male	Select the option that matches the real installation or scenario.
Age	30 years	Measured or known age used by the calculation engine.
Height	175 cm	Measured or known height used by the calculation engine.
Weight	75 kg	Measured or known weight used by the calculation engine.
Activity level	Lightly active — 1–3 days/week	Physical Activity Level (PAL) multiplier applied to BMR.
Goal	Maintain weight	Select the option that matches the real installation or scenario.
Macro split	Balanced 30/40/30	Select the option that matches the real installation or scenario.
Body fat (optional)	0 %	If > 0, Katch-McArdle BMR is also shown (more accurate for lean athletes).

Formula inputs & variables for Calorie Calculator (TDEE & Macros)

These are the named quantities used by this calculator. When the source formula does not define a mathematical symbol, OneCalcApp keeps the real input label instead of inventing one.

Variable / input	Unit	Meaning in this calculation
Sex	—	Select the option that matches the real installation or scenario.
Age	years	Measured or known age used by the calculation engine.
Height	cm	Measured or known height used by the calculation engine.
Weight	kg	Measured or known weight used by the calculation engine.
Activity level	—	Physical Activity Level (PAL) multiplier applied to BMR.
Goal	—	Select the option that matches the real installation or scenario.
Macro split	—	Select the option that matches the real installation or scenario.
Body fat (optional)	%	If > 0, Katch-McArdle BMR is also shown (more accurate for lean athletes).

Formula, derivation and worked example

Basal Metabolic Rate (BMR) is the energy your body burns at complete rest. The Mifflin-St Jeor equation (1990) is the most accurate general-population predictive equation and is the one recommended by the Academy of Nutrition and Dietetics. Multiplying BMR by a Physical Activity Level (PAL) factor gives Total Daily Energy Expenditure (TDEE) — roughly the calories needed to maintain current weight. A deficit or surplus is applied as a percentage of TDEE rather than a fixed number, so the adjustment scales with body size. Macronutrients are then split by calorie share and converted to grams using the Atwater factors: 4 kcal/g for protein and carbohydrate, 9 kcal/g for fat.

BMR (male) = 10·W + 6.25·H − 5·A + 5

BMR (female) = 10·W + 6.25·H − 5·A − 161

TDEE = BMR × PAL

Target kcal = TDEE × (1 + goal%)

Protein g = kcal·P% / 4 · Carbs g = kcal·C% / 4 · Fat g = kcal·F% / 9

Katch-McArdle BMR = 370 + 21.6 × LBM, LBM = W × (1 − BF%)

Substitution steps

1. Basal metabolic rate
10(75) + 6.25(175) − 5(30) + 5
= 1,699 kcal/day
2. Total daily energy expenditure
1,699 × 1.375
= 2,336 kcal/day
3. Goal adjustment
2,336 × (1 + 0%)
= 2,336 kcal/day
4. Protein
2,336 × 30% ÷ 4 kcal/g
= 175 g
5. Carbohydrate
2,336 × 40% ÷ 4 kcal/g
= 234 g
6. Fat
2,336 × 30% ÷ 9 kcal/g
= 78 g

Computed example results

Target calories: 2,336 kcal/day; Maintenance
BMR (Mifflin-St Jeor): 1,699 kcal/day
TDEE (maintenance): 2,336 kcal/day; BMR × PAL 1.375
Protein: 175 g (30%); 2.34 g per kg bodyweight
Carbohydrate: 234 g (40%)
Fat: 78 g (30%)
Expected weight change: 0 kg/week; Using ~7,700 kcal per kg of body mass

Understanding the result

Read the main result together with supporting checks, assumptions, limits and intermediate values.

For a manual check, repeat the first equation, confirm the units and change one input at a time.

Common mistakes when using Calorie Calculator (TDEE & Macros)

Do not mix units for Age (years), Height (cm), Weight (kg). A unit mismatch changes the input magnitude even when the typed number looks reasonable.
Do not leave Sex on the default choice unless that choice matches the real scenario; the selected option can change the calculation path or factor.
Do not replace the displayed BMR (male) = 10·W + 6.25·H − 5·A + 5 relationship with a different convention without also changing the underlying assumptions; compare like-for-like methods when checking the result.
Do not treat Target calories = 2,336 kcal/day from the worked example as a universal answer. It belongs to the displayed example inputs and must be recalculated for the actual case.

When the Calorie Calculator (TDEE & Macros) is useful

Calorie Calculator (TDEE & Macros) is designed for cases where Sex, Age, Height, Weight are known and you need Target calories, BMR (Mifflin-St Jeor), TDEE (maintenance). The page keeps the live calculator, calculation method and worked example together so the result can be checked instead of treated as a black-box number.

Use the calculator for the scope described by its inputs and notes. The displayed method is BMR (male) = 10·W + 6.25·H − 5·A + 5. If the real project or decision needs factors that are not represented here, treat the result as an estimate and add the missing checks separately.

Sex and Age: what changes the answer

The worked example uses Sex = Male, Age = 30 years, Height = 175 cm, Weight = 75 kg. With those values, Target calories is 2,336 kcal/day. Changing an input should be interpreted according to that field's unit, range, option and hint rather than by the number alone.

For this calculator, the main input roles are: Sex: Select the option that matches the real installation or scenario. Available choices include Male, Female. Age (years): Measured or known age used by the calculation engine. Height (cm): Measured or known height used by the calculation engine. Weight (kg): Measured or known weight used by the calculation engine.

How to sanity-check a Calorie Calculator (TDEE & Macros) result

Start by confirming the entered values and units, then compare the substituted working with the displayed formula or calculation steps. Pay particular attention to Target calories, because it is the first worked-example output shown by the live engine.

Finally, compare the result with the assumptions, warnings and related calculators on this page. A nearby calculator can be useful as a cross-check when it measures the same workflow from a different input or output direction.

Next logical calculator

Continue with BMI Calculator

Useful next check because both tools use Weight and Height, while BMI Calculator answers a different part of the same workflow.

Open BMI Calculator

Standards, source trail and limitations

References show the method used. Check the current local edition, amendments and project specification before a regulated decision.

Mifflin MD et al., Am J Clin Nutr 1990;51:241-7
Katch-McArdle / Cunningham lean-mass equation
FAO/WHO/UNU Human Energy Requirements (PAL factors)

Formula

BMR (male) = 10·W + 6.25·H − 5·A + 5
BMR (female) = 10·W + 6.25·H − 5·A − 161
TDEE = BMR × PAL
Target kcal = TDEE × (1 + goal%)
Protein g = kcal·P% / 4 · Carbs g = kcal·C% / 4 · Fat g = kcal·F% / 9
Katch-McArdle BMR = 370 + 21.6 × LBM, LBM = W × (1 − BF%)

Worked example

1Male, 30 y, 175 cm, 75 kg, lightly active, maintain:
2BMR = 10(75) + 6.25(175) − 5(30) + 5 = 1,698.75 kcal/day
3TDEE = 1,698.75 × 1.375 = 2,335.8 kcal/day
4Balanced split → 175 g protein, 234 g carbs, 78 g fat

Assumptions

Predictive equations carry roughly ±10% error versus indirect calorimetry.
PAL multipliers include both exercise and non-exercise activity (NEAT).
Atwater factors 4/4/9 kcal per gram; alcohol (7 kcal/g) is not modelled.
Results assume adults; they are not valid for children, pregnancy or lactation.

Tips

Track weight as a 7-day rolling average and adjust intake by ±100–150 kcal if the trend stalls for 2–3 weeks.
Keep protein at 1.6–2.2 g per kg of bodyweight when in a deficit to protect lean mass.
Keep fat above ~0.6 g/kg for hormone health; the rest of the calories can flex to carbs.
Enter body fat % if you know it — Katch-McArdle is more accurate for very lean or very heavy people.

Warnings

This tool is for general information only and is not medical advice.
Intakes below ~1,200 kcal/day (women) or ~1,500 kcal/day (men) should only be used under clinical supervision.
Consult a doctor or registered dietitian before changing your diet if you have any medical condition.

Standards & references

Mifflin MD et al., Am J Clin Nutr 1990;51:241-7
Katch-McArdle / Cunningham lean-mass equation
FAO/WHO/UNU Human Energy Requirements (PAL factors)

Frequently asked questions

Is my health data sent anywhere?

No. The calorie calculator runs entirely in your browser with JavaScript. Your age, weight, height and body-fat figures are never uploaded, stored on a server or shared.

Which formula does this calorie calculator use?

Mifflin-St Jeor for BMR by default, multiplied by an activity (PAL) factor for TDEE. If you enter a body-fat percentage, the Katch-McArdle equation is shown alongside it.

How many calories should I eat to lose weight?

A 10–20% deficit below TDEE is the usual safe range, giving about 0.5–1% of bodyweight lost per week. Larger deficits increase muscle loss and are harder to sustain.

How accurate is a calorie calculator?

Predictive equations are typically within about 10% of measured energy expenditure. Use the result as a starting point and adjust based on 2–3 weeks of real weight-trend data.

What macro split should I choose?

A balanced 30/40/30 split suits most people. Endurance athletes benefit from more carbs, while low-carb or keto splits are a personal preference — total calories and protein matter most.

What inputs does the Calorie Calculator (TDEE & Macros) use?

It uses Sex, Age, Height, Weight, Activity level, Goal, Macro split, and Body fat (optional). Follow the unit printed for each field and choose any selectable option to match the real scenario.

What does the Calorie Calculator (TDEE & Macros) calculate?

It calculates Target calories, BMR (Mifflin-St Jeor), TDEE (maintenance), Protein, Carbohydrate, Fat, and Expected weight change. With the displayed default inputs, Target calories is 2,336 kcal/day.

Which formula does the Calorie Calculator (TDEE & Macros) use?

The primary relationship is BMR (male) = 10·W + 6.25·H − 5·A + 5. The page also shows substituted values and calculation steps so the result can be checked independently.

Related calculators

Keep going with more health tools.

BMI Calculator

Calculate Body Mass Index with the WHO classification, healthy weight range and BMI Prime, in metric or imperial units.

Age Calculator

Calculate exact age in years, months and days from a date of birth, plus total weeks, days, hours and the next birthday countdown.

Percentage Calculator

Solve every common percentage problem: X% of Y, what percent one number is of another, percentage increase or decrease and reverse percentage.

BMR Calculator

Find your basal metabolic rate — the calories your body burns at complete rest.

TDEE Calculator

Calculate total daily energy expenditure and the calorie targets for cutting, maintaining or bulking.

Child Growth Calculator

Check a child's BMI-for-age and estimate their adult height from the parents' heights.