TDEE Calculator — How Many Calories Should You Eat a Day?
Work out your Total Daily Energy Expenditure and get daily calorie, protein, carb and fat targets — then see which GYG, Zambrero, Fishbowl or Subway meals actually fit them.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories you burn per day: your basal metabolic rate (the energy your body uses at rest) multiplied by an activity factor. Eat at your TDEE to maintain weight, below it to lose, above it to gain. This calculator estimates BMR with the Mifflin-St Jeor equation, the standard formula best supported by research.
The activity multiplier is where most people go wrong — training three times a week doesn't make a desk worker “very active”. Pick honestly:
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | desk job, little or no exercise | ×1.2 |
| Lightly active | exercise 1–3 days a week | ×1.375 |
| Moderately active | exercise 3–5 days a week | ×1.55 |
| Very active | hard exercise 6–7 days a week | ×1.725 |
| Extremely active | physical job plus hard training | ×1.9 |
How your macro targets are set
Protein is set at 1.8 g per kilogram of bodyweight — the middle of the 1.6–2.2 g/kg range the sports-nutrition evidence supports for keeping or building muscle. Fat gets 30% of your calories (hormone and absorption baseline), and carbohydrates fill the remainder to fuel training and daily activity. They're targets, not rules — hitting calories and protein consistently matters far more than the exact carb/fat split.
Put your targets to work
A target is only useful if you can check real food against it. Build your actual order in the GYG calorie calculator, the Zambrero calculator, the Fishbowl calculator or the Subway calculator and compare the macros to your daily numbers.
Cutting? Start with the GYG meals under 500 calories or the lowest-calorie GYG meals. Chasing protein? See the highest-protein GYG meals and the most protein-efficient picks, or browse the full GYG menu with calories.
TDEE calculator — frequently asked questions
How many calories should I eat a day?
It depends on your size, age, sex and activity: your Total Daily Energy Expenditure (TDEE) is the number of calories you burn per day, and eating that amount maintains your weight. Use the calculator above — most Australian adults land between roughly 1,800 and 3,000 calories a day. Eat below your TDEE to lose weight, above it to gain.
What is TDEE and how is it calculated?
TDEE (Total Daily Energy Expenditure) is your basal metabolic rate (BMR) — the energy your body uses at rest — multiplied by an activity factor. This calculator uses the Mifflin-St Jeor equation for BMR, which research supports as the most accurate standard formula, then multiplies by a factor from 1.2 (sedentary) to 1.9 (extremely active).
How accurate is a TDEE calculator?
It's a well-evidenced estimate, typically within about 10% for healthy adults — individual metabolism, muscle mass and daily movement vary. Treat the number as a starting point: track your weight for 2–3 weeks and adjust your intake up or down by 100–200 calories if you're not moving toward your goal.
How much protein should I eat a day?
For people who train, the evidence supports roughly 1.6–2.2 grams of protein per kilogram of bodyweight per day. This calculator uses 1.8 g/kg — for an 80 kg person that's about 144 g of protein a day. Fat is set at 30% of calories and carbohydrates make up the remainder.
How many calories should I eat to lose weight?
A deficit of about 500 calories below your TDEE loses roughly 0.5 kg per week — sustainable for most people. Avoid very low intakes (below about 1,200–1,500 calories a day) without medical advice, and prioritise protein to keep muscle while cutting.
What about kilojoules? Australian labels use kJ.
Multiply calories by 4.184 to get kilojoules — a 2,000-calorie target is about 8,370 kJ. Australian menu boards and labels legally show kilojoules; this site shows both for every menu item.
How do I use my targets when eating out?
Save your target here, then build your actual order in the GYG, Zambrero, Fishbowl or Subway calculators on this site to see exactly how a meal fits your day — for example, a 700-calorie burrito is about a third of a 2,100-calorie target.