TDEE and maintenance calories explained for people who train

Maintenance calories are the daily energy that keeps your weight roughly stable. TDEE (total daily energy expenditure) is the fuller picture: BMR at rest, plus movement, training, and the small cost of digesting food. Online calculators estimate TDEE with the Mifflin-St Jeor equation times an activity factor; the equation was derived from 498 healthy adults and is the usual default because later validation work found it closer to measured resting rate than older formulas. For people who train, the useful move is not memorising a number forever but starting from an estimate, eating enough protein, and adjusting after two to three weeks using a 7-day average weight trend.

TL;DR

Piece	What it means
BMR / resting rate	Energy at complete rest; largest share of TDEE for most people
TDEE	Resting rate × activity factor (1.2 sedentary up to ~1.9 for heavy training)
Maintenance	Eat near TDEE; weight trend stays flat
Fat loss	Often 250–500 kcal/day below maintenance → ~0.25–0.5 kg/week for many adults
Muscle gain	Small surplus (~200–300 kcal/day) with progressive lifting and high protein
Reality check	Do not add watch “burn” on top of TDEE; pick the honest activity level

Run your numbers in the TDEE calculator, then cross-check protein with the protein calculator.

What is TDEE in plain language?

Think of your body like a car that idles all day. Even lying on the sofa, you burn fuel to keep your heart beating, lungs working and cells repairing. That idle cost is close to basal metabolic rate (BMR). Add walking to work, lifting, fidgeting, digesting lunch, and a hard interval session, and you reach total daily energy expenditure.

Researchers split TDEE into components:

1. Basal or resting metabolism — roughly 60–70% of TDEE for sedentary people; a bit less when activity is high.
2. Activity — purposeful exercise plus non-exercise activity thermogenesis (NEAT), such as stairs, pacing on calls and cooking.
3. Thermic effect of food (TEF) — roughly 10% of intake to digest and process food; protein has a slightly higher TEF than fat or carbohydrate.

You never see those buckets on a bathroom scale. What you do see is whether average intake is above, below or equal to average expenditure over weeks.

How do calculators estimate maintenance calories?

Most consumer tools, including revns, use resting metabolic rate (RMR) equations when lab measurement is unavailable. Mifflin-St Jeor is the default because it performed well across body sizes in validation work.

The Mifflin-St Jeor equation

For weight in kilograms, height in centimetres, and age in years:

• Men: RMR = 10 × weight + 6.25 × height − 5 × age + 5
• Women: RMR = 10 × weight + 6.25 × height − 5 × age − 161

Example: a 30-year-old woman at 65 kg and 165 cm:

10 × 65 + 6.25 × 165 − 5 × 30 − 161 = 1,396 kcal/day (rounded) at rest.

A 30-year-old man at 80 kg and 178 cm:

10 × 80 + 6.25 × 178 − 5 × 30 + 5 = 1,778 kcal/day (rounded) at rest.

Mifflin and colleagues measured resting expenditure in 498 healthy subjects (ages 19–78, normal-weight and obese) and published the sex-specific formulas above. That is why calculators call the output an estimate, not a diagnosis—later studies still report meaningful error in some people, especially at extremes of age or adiposity.

Activity factors

The resting number is multiplied by an activity factor to approximate TDEE:

Label	Factor	Typical day
Sedentary	1.2	Desk job, little deliberate exercise
Lightly active	1.375	Light training or walking most days
Moderately active	1.55	3–5 days/week purposeful training
Very active	1.725	Hard training most days or physical job
Athlete / extra heavy	1.9	Twice-daily sessions or very demanding labour

Using the woman above at 1.55:

1,396 × 1.55 ≈ 2,160 kcal/day estimated TDEE.

Most people overestimate activity. If your job is mostly seated and you train three evenings a week, 1.375–1.55 is usually more honest than 1.725. When unsure, choose the lower factor and let the scale tell you whether to add food.

What is the difference between BMR, RMR and TDEE?

Term	Measured how?	What it includes
BMR	After an overnight fast, full rest, in a lab	Absolute minimum to stay alive
RMR	Morning, rested, less strict protocol	Slightly higher than BMR; what equations approximate
TDEE	Doubly labelled water in research; calculators use factors	RMR + all movement + TEF

In conversation, BMR and RMR are often used interchangeably on apps. What matters for your kitchen is TDEE: the number that, if eaten every day for a month, leaves weight flat.

How do I use maintenance calories to lose fat?

Fat loss needs a sustained calorie deficit: intake below expenditure. The scale moves slowly because water, glycogen and gut contents hide fat change for days.

A moderate deficit that protects training

NHLBI overweight-and-obesity guidance often targets a 500 to 1,000 kcal/day reduction from usual intake for about 0.5 to 1 kg (1–2 lb) per week, while very low intakes need medical supervision. For lifters, 250–500 kcal/day below estimated TDEE is often enough for ~0.25–0.5 kg fat per week without turning every session into a slog.

Pair the deficit with:

• Protein around 1.8–2.2 g/kg if you resistance train (protein guide)
• Progressive strength work two to four days a week (beginner strength plan)
• Sleep in a range that keeps sessions productive (sleep needs)

Why “3,500 calories = one pound” is oversimplified

Early rules assumed 1 lb (0.45 kg) fat ≈ 3,500 kcal. Kevin Hall showed that shortcut does not fit every body and that changing body composition alters how much deficit each kilogram lost needs—so real loss is often slower than a straight-line calorie tally predicts. Treat calorie math as direction, not a daily contract. If the 7-day average weight is flat for 14 days, intake is probably at maintenance, not deficit.

Do not “eat back” exercise calories

Watch and treadmill estimates of burn are noisy. TDEE multipliers already include your typical training. Logging food to maintenance and adding 600 kcal because a watch said so usually double-counts. Keep the same food target; adjust from trend, not from yesterday’s spin class.

How do I gain muscle without excessive fat?

Muscle gain needs training stimulus, protein, and often a small energy surplus. Many coaches use ~200–300 kcal/day above maintenance while running a structured hypertrophy block. Larger surpluses raise scale weight faster but add fat unless you are a rank beginner.

Practical checks:

• Strength on main lifts trends up over 4–8 weeks
• Protein stays high; meals need not be “dirty”
• Weekly gain much above 0.5 kg for months may be mostly water and fat

revns does not prescribe meal plans; use meal tracking to note on-plan meals and portion habits instead of counting every gram if that style suits you (alternatives to calorie apps).

Why can two people with the same TDEE lose weight differently?

Equations ignore factors that shift real expenditure:

• NEAT — some people unconsciously move more when overfed; others slow down when dieting.
• Sleep debt — short sleep can change hunger hormones and food choices in controlled studies.
• Stress and illness — temporary water retention masks fat loss on the scale.
• Menstrual cycle — many women see ±1–2 kg water shifts across the cycle; use monthly averages, not one pre-period weigh-in.
• Medication — several drugs change appetite or resting rate; follow your prescriber’s advice.

That is why individual trend beats arguing about 50 kcal in an app.

What should you do this week?

1. Estimate TDEE with the calculator. Pick the lower activity level if you are unsure.
2. Weigh yourself 3–4 mornings after the bathroom, before food. Record in notes or revns; ignore single spikes.
3. Compute a 7-day average after one week. Compare to the prior week if you changed food.
4. Set protein first at about 1.6–2.0 g/kg if you train; fill remaining calories with mostly whole foods you already cook (dal, rice, roti, eggs, paneer, tofu, fish, chicken, vegetables, fruit, yoghurt).
5. Hold the calorie target 14 days before changing it. Adjust by 100–150 kcal if weight trend is flat and the goal is fat loss (or gain).
6. Log training and sleep next to food if you use an AI coach (mood and energy) so deload weeks are visible.

Vegetarian, vegan and mixed households

Maintenance calories do not care about diet pattern. Dal + rice, chole + roti, tofu stir-fry, eggs and toast, or fish curry can all hit the same TDEE target; protein anchors matter more than the label on the diet.

When should you see a professional?

Get clinical advice before aggressive dieting if you have diabetes, kidney disease, heart failure, pregnancy or breastfeeding, or a history of eating disorders.

Stop and seek urgent care for chest pain, fainting, blood in vomit or stool, or rapid unexplained weight loss.

For mental health crises related to food or body image, contact a qualified clinician or local crisis line; an app or calorie target is not treatment.

Related

• TDEE calculator
• How much protein do you need a day?
• MyFitnessPal and Cronometer alternatives
• Strength training for beginners
• Meal tracking

This is general training and nutrition guidance, not medical advice.

Sources

• Mifflin MD et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990
• Hall KD. What is the required energy deficit per unit weight loss? Int J Obes 2008
• U.S. National Heart, Lung, and Blood Institute. Practical guide to overweight and obesity in adults
• U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans 2020–2025