TDEE & Daily Calorie Needs

Mifflin-St Jeor equation with activity weighting — the same starting point we use in an assessment.

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Fill in your details and hit calculate.
Your maintenance and goal calories will appear here.

Macro Split Calculator

Protein set per kilogram of bodyweight, fat as a share of total calories, carbohydrate filling the remainder.

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Enter your details to see your protein,
carbohydrate and fat targets in grams.

Body Mass Index

A population screening tool. Useful as context, poor at describing muscular athletes — read the note under your result.

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Enter your height and weight
to see your BMI and healthy weight range.

Daily Hydration Target

Baseline requirement scaled to bodyweight, plus replacement for training losses and climate.

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Enter your weight and training volume
for a daily fluid target.

Reference Weight Range

Four clinical formulas averaged, adjusted for frame size, shown alongside the healthy BMI weight range.

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Enter your height and frame size
to see your reference weight range.

01 — Interpretation

Every equation here is built on population averages. Your actual expenditure can sit 200–400 calories either side of the estimate.

A calculator gives you a starting point, not a verdict.

01

Start With the Estimate

Take the calculated target and hold it steady for a full fourteen days. Don't adjust mid-week on a single scale reading.

02

Track the Trend

Weigh daily, then compare seven-day averages. Day-to-day swings of two to four pounds are water and food volume, not fat.

03

Adjust From Reality

If the trend isn't moving at the intended rate after two weeks, change calories by 5–10% — not by a third.

⚠️ Important

These calculators are educational tools for generally healthy adults. They are not appropriate for children, during pregnancy or breastfeeding, or for anyone with a diagnosed metabolic, cardiac, renal or eating disorder. If any of those apply, speak to your physician or a registered dietitian before acting on any result. See our full Disclaimer.

02 — Questions

What's behind the maths.

Calculator questions.

Mifflin-St Jeor for basal metabolic rate, multiplied by a standard activity factor from 1.2 (sedentary) to 1.9 (athlete). Mifflin-St Jeor is generally the most accurate of the widely used predictive equations for the general population, though it still carries meaningful individual error.
Because in an energy deficit protein is doing defensive work — preserving lean tissue while you lose fat. That job needs more protein than muscle gain does, which surprises most people. Our fat loss setting uses roughly 2.2 g per kilogram of bodyweight.
Not useless, but easily misread. BMI cannot distinguish muscle from fat, so a lean, muscular person is routinely classified as overweight. Use waist circumference and body fat percentage as your primary measures and treat BMI as background context only.
No. Every calculation runs entirely inside your browser. Nothing you type is transmitted to us or to any third party, and nothing is saved when you close the page.
That's expected for a meaningful minority of people — predictive equations have real individual error, and factors like previous dieting history, thyroid function and non-exercise activity aren't captured. That gap is precisely what a measured assessment resolves.
03 — Next

An estimate is a starting line, not a plan.

We take these same numbers, measure what the equations can only guess at, and adjust them every two weeks against your actual results.

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