Protect Your Orderi
from Loss, Damage Or Stolen A$2.09
Calorie Calculator
How many calories a day, for your goal, in three steps. Free, and you do not need to hand over an email to see the number.
The short answer
Your daily calorie target is your estimated maintenance adjusted for your goal. Maintenance is your resting energy multiplied by how active you are, and the adjustment is a percentage of that rather than a flat number, so it scales with the size of the person.
- Losing fat applies a reduction against maintenance and is capped at 1% of bodyweight per week.
- Your target never drops below the higher of your resting energy and an absolute floor.
- You get a working range, not a single number, because every estimate of this kind carries real error.
- 1. About you
- 2. Activity
- 3. Goal
About you
These four details set your baseline. Metric units, since this is built for Australia.
years
cm
kg
If you know it from a DEXA or InBody scan, this makes the estimate more accurate. Leave it blank if you are guessing.
%Two quick checks
If either applies to you, generic calorie targets are the wrong tool and we will point you somewhere better instead.
How your calorie target is worked out
It happens in three stages. First your resting energy, which is what you would burn doing nothing at all. Then your maintenance, which is resting energy multiplied by how active you are. Then your target, which is maintenance adjusted for what you are trying to do.
Most of the variation between two people of the same weight comes from that middle stage. Two people at 80 kg can sit thousands of calories apart on maintenance depending on their job and their training.
- Losing fat: maintenance minus 18%.
- Recomposition: maintenance minus 5%.
- Maintaining: your maintenance estimate.
- Building muscle: maintenance plus 10%.
- Gaining size: maintenance plus 15%.
Why you get a range and not just one number
Every calorie estimate is an estimate. The equations behind them were built from population averages, so for any individual they carry real error, and food labels carry error of their own on top.
That is why the results page shows a working range either side of the number. Hitting the range consistently tells you more than hitting a single figure occasionally, and if your weight is not moving the way you expected after a few weeks, the honest answer is to adjust from what actually happened rather than to trust the estimate harder.
How these numbers are produced
Every figure on the results page comes from a fixed calculation, not from an AI guess. The same answers always produce the same numbers, which is why you can come back next month, enter the same details, and get the same targets.
An AI model writes the explanation you read underneath the numbers. It is given the figures after they have been calculated and it is not allowed to change them, recalculate them, or quote a figure the calculation did not produce.
- Resting energy is estimated with the Mifflin-St Jeor equation, or the Katch-McArdle equation if you tell us your body fat percentage, which is the more accurate of the two when that figure is known.
- Your activity multiplier comes from your weekly training sessions and how physical your work day is. The scale runs from 1.2 for sedentary to 1.9 for very high activity.
- We deliberately lean conservative on activity. Overestimating maintenance is the most common failure in consumer calculators, and it quietly makes every goal harder.
The limits built into this calculator
A calorie target handed to a stranger needs guardrails, so several are built in and cannot be overridden.
- Fat loss is capped at 1% of your bodyweight per week. Faster than that is not a setting you can choose here.
- Your calorie target never drops below the higher of your estimated resting energy and an absolute floor of 1500 calories for men or 1200 for women.
- There are no goal weight projections and no "you will reach X by this date" timelines, because those numbers are not knowable and they set people up to feel they have failed.
- If your details fall outside what a general calculator should answer, it stops and points you to a doctor or an Accredited Practising Dietitian instead of producing a number anyway.
Fibre and water
Fibre is set at 14 g per 1000 calories, so it scales with how much you are eating. The Australian Nutrient Reference Values set an Adequate Intake of 30 g per day for men and 25 g per day for women, so on most targets this calculator will land above the Australian figure rather than below it.
Water is estimated at 35 ml per kg of bodyweight, with an allowance added on training days. It is a starting point, not a rule. Heat, sweat rate and what you eat all move it.
What this calculator is not
This is general information. It is not personalised dietary advice and it is not medical advice. It cannot see your blood work, your training history, your medication or your relationship with food.
If you are managing a health condition, if you are pregnant or breastfeeding, if you have a history of disordered eating, or if you simply want targets built around your actual situation, speak to a doctor or an Accredited Practising Dietitian. That is a better use of your time than any calculator.
Common questions
How many calories should I eat to lose weight?
This calculator sets fat loss at your maintenance estimate minus 18%, and caps the rate at 1% of bodyweight per week. It will not go below the higher of your resting energy estimate and an absolute floor, so the number you get is bounded on purpose rather than being as low as you might want.
Why is my target higher than a calculator I used before?
Usually one of two reasons. Either the other calculator was more generous with the activity multiplier, which is common, or it applied a steeper deficit than the cap here allows. This one leans conservative on activity because overestimating maintenance makes every goal harder without telling you why.
Does the calculator account for exercise separately?
Your training is already inside the activity multiplier, so you should not add calories back for a session you have already told us about. Adding exercise calories on top of an activity multiplier that includes them is the most common way people accidentally eat at maintenance while believing they are in a deficit.
How long before I should change the number?
Give it a few weeks of consistent eating before judging it, and weigh the trend rather than any single day. Bodyweight moves for reasons that have nothing to do with fat, particularly water, food volume and where you are in your week.
