Important: Energy requirements are highly individual and depend on age, sex, body composition, activity level, metabolic rate and health status. The values below are estimates for general reference. For personalised dietary advice, consult an Accredited Practising Dietitian.

Understanding Energy Units

In Australia, food energy is measured in kilojoules (kJ). The calorie (kcal) is also commonly used. The conversion is: 1 kcal = 4.184 kJ. Australian food labels display energy in kJ per serving and per 100 g.

Estimated Daily Energy Requirements

The following table provides approximate daily energy requirements based on the Australian Nutrient Reference Values, assuming moderate activity levels.

GroupAgeApprox. kJ/dayApprox. kcal/day
Men (sedentary)19–508,7002,080
Men (moderately active)19–5010,3002,460
Men (active)19–5012,2002,915
Women (sedentary)19–506,8001,625
Women (moderately active)19–508,0001,910
Women (active)19–509,8002,340
Adolescents (boys)14–1810,200–12,6002,440–3,010
Adolescents (girls)14–187,600–9,0001,815–2,150
Older adults (men)70+7,800–9,6001,865–2,295
Older adults (women)70+6,300–7,6001,505–1,815

Basal Metabolic Rate (BMR) Estimation

BMR represents the energy your body requires at rest to maintain basic physiological functions. It accounts for approximately 60–75% of daily energy expenditure in sedentary individuals.

The Mifflin-St Jeor equation is commonly used to estimate BMR:

Men: BMR (kcal) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5

Women: BMR (kcal) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161

To estimate total daily energy expenditure (TDEE), multiply BMR by an activity factor:

Activity LevelDescriptionMultiply BMR by
SedentaryDesk job, little or no exercise1.2
Lightly activeLight exercise 1–3 days/week1.375
Moderately activeModerate exercise 3–5 days/week1.55
Very activeHard exercise 6–7 days/week1.725
Extremely activePhysical job + daily intense training1.9

Energy Content of Common Foods

The following table lists approximate energy values for common foods available in Australia. Values are per standard serving size.

FoodServing SizekJkcalProtein (g)
Rolled oats (cooked)1 cup (240 g)6901656
Chicken breast (grilled)150 g92022042
Brown rice (cooked)1 cup (195 g)9202205
Banana1 medium (120 g)4401051
Greek yoghurt (plain, low-fat)170 g42010017
Avocado½ medium (75 g)5001201.5
Wholegrain bread1 slice (40 g)380904
Salmon fillet (grilled)150 g1,16027534
Sweet potato (baked)1 medium (150 g)5401302
Eggs (boiled)2 large62015013
Broccoli (steamed)1 cup (90 g)130312.5
Almonds30 g (small handful)7301756

Values are approximations and may vary depending on preparation method, brand and exact portion size. Source: Food Standards Australia New Zealand (FSANZ) nutrient database.

Macronutrient Energy Values

Each macronutrient provides a different amount of energy per gram:

MacronutrientEnergy per gramRole
Carbohydrates17 kJ (4 kcal)Primary energy source for brain and muscles
Protein17 kJ (4 kcal)Tissue repair, immune function, enzyme production
Fat37 kJ (9 kcal)Energy storage, hormone production, nutrient absorption
Alcohol29 kJ (7 kcal)Not an essential nutrient; provides energy but no nutritional benefit

Disclaimer: This page provides reference information for educational purposes. It is not a personalised meal plan or diagnostic tool. Energy requirements and dietary needs are individual. Consult an Accredited Practising Dietitian for advice tailored to your specific circumstances.