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ElenaFitness Free Calculator

Evidence-based coaching

Sustainable Fat Loss.
No Crash Diets.

Work out exactly how much you should eat, how much protein you need, and why the slow way is the only way that lasts. Free, no sign-up, no gimmicks.

Coaching since
2013
Clients guided
1,400+
Cost
Free

What you'll get in 60 seconds

  • Maintenance calories — the energy you burn on an average day, based on the Mifflin-St Jeor equation.
  • A fat-loss target — a moderate deficit you can actually hold for months, not days.
  • Daily protein — the single most protective nutrient for keeping muscle while you lose fat.
  • Context — plain-English guidance on what to do with those numbers.

Follow along

Daily coaching on Instagram

Form check videos, high-protein meals from a real kitchen, and honest progress updates from clients who took the slow route. No before-and-after gimmicks.

@elena_fitness_coach1

TDEE & Protein Calculator

Enter your details below. We use the Mifflin-St Jeor equation for basal metabolic rate, multiply by an activity factor for total daily energy expenditure, and apply a moderate 20% deficit for fat loss.

Your details

Your results

Maintenance calories
Fat loss calories (-20%)
Daily protein target
Basal metabolic rate

Results are estimates. Track your weight for two weeks and adjust by 100-150 calories if the trend isn't moving.

The Elena Philosophy: How to Lose Fat Sustainably

Written by Elena Marsh, certified personal trainer and nutrition coach · Reviewed August 2026 · ~9 minute read

1. Why Crash Diets Fail

Almost everyone who walks into my studio has already lost the same ten kilos two or three times. They know how to lose weight. What nobody taught them is how to keep it off, and that is a completely different skill. Crash diets fail so reliably that the failure is practically built into the design, and understanding why is the first step towards never needing one again.

The first problem is the size of the deficit. When you cut calories by 40-50% overnight, your body cannot tell the difference between a deliberate diet and a genuine food shortage. It responds the way it has responded for a few hundred thousand years: hunger hormones such as ghrelin climb, satiety hormones such as leptin fall, and the small unconscious movements that make up a surprising share of your daily energy burn — fidgeting, pacing, gesturing, taking the stairs — quietly decrease. Researchers call this adaptive thermogenesis. In practice it means the deficit you calculated on paper shrinks in the real world, so you have to cut even harder to keep the scale moving. That is a race nobody wins.

The second problem is muscle. In a very aggressive deficit, especially one with low protein and no resistance training, a meaningful portion of the weight you lose is lean tissue rather than fat. Muscle is metabolically active and it is the tissue that makes you look toned rather than simply smaller. Lose it and your maintenance calories drop, which means the weight you regain later comes back onto a body that now burns less than it used to. This is the mechanism behind the depressing pattern of ending each diet cycle a little softer than you started.

The third problem is behavioural, and it is the one I care about most. Crash diets rely on rules you cannot live with: no carbohydrates, no eating after seven, no restaurants, no bread, no wine at your sister's wedding. Rules like these work brilliantly for four weeks and then collapse, and the collapse feels like a personal failure rather than what it actually is — a predictable response to an unliveable plan. The shame that follows sends people straight back to the next extreme protocol, and the cycle repeats.

The alternative is dull and it works. A deficit of roughly 15-25% below maintenance, which for most people means somewhere between 300 and 600 calories, produces fat loss of around 0.5-1% of body weight per week. That is slow enough that hunger stays manageable, training performance holds up, and the habits you build in month one are the same habits you will still be using in month eight. Nobody makes a documentary about that. It is simply the version that lasts.

2. The Power of Protein

If I could only change one thing about the average diet, it would not be carbohydrates, sugar, or eating windows. It would be protein. Protein does three things at once during fat loss, and no other nutrient comes close.

First, it protects muscle. When you are eating less than you burn, your body needs amino acids and will take them from wherever it can, including your own tissue. A high protein intake combined with two or three resistance sessions a week gives your body a strong signal to hold on to lean mass and take the energy from fat stores instead. The practical result is that two people can lose the same eight kilos and look entirely different at the end of it.

Second, protein keeps you full. Gram for gram it is the most satiating macronutrient, and that effect compounds across a day. A breakfast built around eggs, Greek yoghurt, tofu or cottage cheese changes how the rest of your day feels: the eleven o'clock crash softens, the afternoon biscuit habit loosens its grip, and evening meals stop needing to be enormous to feel satisfying. Adherence is the whole game in fat loss, and satiety is what makes adherence possible.

Third, protein is expensive to digest. Roughly 20-30% of the calories in protein are burnt during digestion and absorption, compared with about 5-10% for carbohydrates and 0-3% for fats. It is not a magic trick and it will not out-run a large surplus, but across months it is a real and free advantage.

How much? For most people in a deficit, somewhere between 1.6 and 2.2 grams per kilogram of body weight per day is the well-supported range, and the calculator above uses 1.8 g/kg as a sensible middle. If you carry a lot of excess body fat, calculating from a target weight rather than current weight is more practical. Spread it across three or four meals rather than cramming it into dinner, and lean on the boring reliable sources: chicken, white fish, lean beef, eggs, dairy, legumes, tofu, tempeh, and a scoop of whey or pea protein when real food is inconvenient. If you consistently hit your protein and your total calories, the rest of the diet has a remarkable habit of sorting itself out.

3. Consistency Over Perfection

The clients who succeed are almost never the most disciplined ones. They are the ones with the shortest recovery time after a bad day. A single unplanned meal has almost no measurable effect on a monthly average; the damage comes from the four days of "I've ruined it anyway" that follow. Learning to eat one indulgent dinner and then have an entirely ordinary breakfast the next morning is worth more than any supplement, tracking app or training split.

Build the plan around your actual life. If you travel every second week, a plan that requires meal prep every Sunday is already broken. If you hate running, do not build your programme on running. Choose the foods you genuinely enjoy, keep two or three default meals you can make on autopilot when you are tired, and accept that an eighty-percent version you follow for a year beats a perfect version you follow for eleven days.

Measure the process, not just the outcome. Body weight fluctuates by a kilo or more from salt, carbohydrate intake, hormonal cycles and how recently you trained, so a single reading tells you almost nothing. Weigh yourself several mornings a week and compare weekly averages, and pair that with things the scale cannot see: waist measurements, how a pair of jeans fits, the weight on the bar, your sleep, your energy at four in the afternoon. When progress stalls for three or four weeks at a stable average, that is the moment to trim another 100-150 calories or add a little more daily walking — not before.

Finally, plan for the end. A fat loss phase should have a finish line. When you reach your target, spend a few weeks deliberately eating back up to maintenance and holding there so your body, your habits and your relationship with food all get to practise stability. Maintenance is not the absence of a goal; it is the goal. Everything before it is just the part that got you here.

About Elena

Elena Marsh has coached in-person and online since 2013, working mainly with busy professionals and post-partum clients who have a history of yo-yo dieting. She holds a Level 3 Personal Training qualification and a nutrition coaching certification, and she writes everything on this site herself. Elena Fitness does not sell supplements and has no affiliate relationships with supplement brands; the calculator and the guidance here are free and always will be.

Frequently asked questions

How accurate is a TDEE calculator?

Equations like Mifflin-St Jeor are typically within about 10% for most people. Treat the number as a starting point, then adjust based on two to three weeks of real-world weight data.

Should I eat back the calories I burn in exercise?

No — the activity multiplier already accounts for your training. Adding tracker-estimated burn on top usually double-counts and erases the deficit.

Do I have to count calories forever?

Most people track for a few months to build accurate portion intuition, then move to a lighter approach: tracking protein only, or checking in for a week each month.

Is a lower deficit better if I'm in a hurry?

Going below roughly 1,200 calories for women or 1,500 for men is rarely necessary and makes hunger, muscle loss and rebound far more likely. Speed is not the constraint; adherence is.