
A kilojoule (like a calorie) is a measure of energy in food. On average, people eat and drink around 8700 kilojoules a day, however we're all different.
To maintain your current weight, use your current (actual) body weight in the calculator below.
To lose or gain weight, use your ideal body weight in the calculator below. This will give you an estimated daily kilojoule requirement to help you meet your weight loss (or gain) goal. You can find your ideal body weight for your height by using this BMI calculator (a healthy weight range for an adult is a BMI between 20 and 25).
Kilojoule calculator
Note: If your work/occupation fits into 'Very sedentary', 'Sedentary', 'Lightly active' or 'Moderately active' and you exercise strenuously (30 to 60 minutes, 4 to 5 times per week), change your selection to the next highest level of activity.
If your current weight is outside your healthy weight range (BMI 20-25), enter your ideal/healthy weight rather than your current weight. You can find your ideal/healthy weight for your height by using this BMI Calculator.
Your daily energy requirements
If pregnant you may require additional energy:
- 1st trimester - No additional requirements
- 2nd trimester - Additional 1400 kJ/day
- 3rd trimester - Additional 1900 kJ/day
If breastfeeding:
- Additional 2000-2100 kL/day
This calculation show you approximately how many kilojoules you need each day to maintain your weight or get closer to your weight goal over a healthy period.
Everyone is different, and this is just a starting point. A good way to tell whether you are consuming the right amount of kilojoules is whether you are gaining or losing weight.
To achieve and maintain a healthy weight, it helps to check your weight regularly - try monthly, then adjust your food choices and physical activity levels depending on the results.
The good news is that small changes can make a big difference. You can find more information on healthy eating and physical activity on our website. For personalised advice, consult an accredited practising dietitian or health professional.
- Calculator results are based on population averages and are approximations. Individual needs are likely to vary
- If you want a tailored, personal weight management plan, you should consult your doctor or accredited practising dietitian
- This calculator is provided for instruction and is not intended for medical diagnosis or treatment
- It doesn't provide for pregnant or breastfeeding women, and may be less suitable for people involved heavily in sporting activities, with some health conditions or for ethnicities whose weight-to-age ratio differs from the population average
- Calculations are based on the approach by McNeil, in Garrow, James & Ralph (eds) 2000, Human nutrition.

Based on material provided by the National Health and Medical Research Council
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