How many calories should I eat per day to lose weight?

Most adults can lose weight safely by eating 6,000-8,000 kJ (1,400-1,900 kcal) per day, but the exact number depends on your size, age, gender, and activity level. Use this calculator to get a personalised target rather than following a generic number.

Should I count kilojoules or calories?

In Australia, food labels show kilojoules (kJ). However, many diet plans and international resources use calories (kcal). Either unit works — just be consistent. 1 kcal equals 4.184 kJ. Our calculator shows both for your convenience.

What is the 8,700 kJ figure on Australian food labels?

The 8,700 kJ (2,080 kcal) reference value on Australian food labels is an average daily energy intake for adults. It is a rough guide only and does not account for your individual size, age, gender, or activity level. Most people need more or less than this amount.

How do I adjust my calories if I hit a plateau?

If your weight loss stalls for more than 2 weeks, recalculate your calorie needs using your current weight. You can also try increasing your activity level, incorporating resistance training, or cycling between higher and lower calorie days.

Calorie Calculator

Find out exactly how many kilojoules or calories you need each day based on your body stats, activity level, and goal. This calculator provides personalised targets for weight loss, maintenance, and weight gain.

Enter Your Details

Gender

Age

years

Weight

Height

Activity Level

Goal

How It Works

Your daily calorie needs are calculated by first estimating your BMR using the Mifflin-St Jeor equation, then multiplying by an activity factor to get your TDEE. For weight loss, a 20% deficit is applied. For maintenance, your full TDEE is used. For weight gain, a 10-15% surplus is added.

Quick Reference

Profile	Goal	Daily kJ	Daily kcal	Protein (g)
Female 55 kg, sedentary	Lose	5,380	1,286	129
Female 65 kg, light	Lose	6,316	1,510	151
Female 65 kg, moderate	Maintain	8,401	2,008	201
Female 75 kg, active	Gain	10,755	2,571	193
Male 70 kg, sedentary	Lose	6,564	1,569	157
Male 80 kg, light	Lose	7,633	1,825	182
Male 80 kg, moderate	Maintain	10,498	2,510	251
Male 90 kg, active	Gain	13,515	3,230	242

All profiles assume age 30, average height. Protein calculated at 40% for weight loss, 30% for maintenance/gain.

Frequently Asked Questions

How many calories should I eat per day to lose weight?: Most adults can lose weight safely by eating 6,000-8,000 kJ (1,400-1,900 kcal) per day, but the exact number depends on your size, age, gender, and activity level. Use this calculator to get a personalised target rather than following a generic number.
Should I count kilojoules or calories?: In Australia, food labels show kilojoules (kJ). However, many diet plans and international resources use calories (kcal). Either unit works — just be consistent. 1 kcal equals 4.184 kJ. Our calculator shows both for your convenience.
What is the 8,700 kJ figure on Australian food labels?: The 8,700 kJ (2,080 kcal) reference value on Australian food labels is an average daily energy intake for adults. It is a rough guide only and does not account for your individual size, age, gender, or activity level. Most people need more or less than this amount.
How do I adjust my calories if I hit a plateau?: If your weight loss stalls for more than 2 weeks, recalculate your calorie needs using your current weight. You can also try increasing your activity level, incorporating resistance training, or cycling between higher and lower calorie days.

How This Is Calculated

BMR (kcal) = 10 × weight + 6.25 × height − 5 × age ± gender constant TDEE = BMR × Activity Factor Weight Loss Target = TDEE × 0.80 Maintenance Target = TDEE Weight Gain Target = TDEE × 1.10

BMR: = Basal Metabolic Rate (Mifflin-St Jeor)
TDEE: = Total Daily Energy Expenditure
0.80 / 1.10: = 20% deficit for loss, 10% surplus for gain

Macro splits: Weight loss = 40% protein, 30% carbs, 30% fat. Maintenance = 30% protein, 40% carbs, 30% fat. Gain = 30% protein, 45% carbs, 25% fat.

Related Tools

TDEE Calculator

Calculate your Total Daily Energy Expenditure using the Mifflin-St Jeor equation. See how many calories and kilojoules you burn per day.

Calorie Deficit Calculator

Calculate your optimal calorie deficit for weight loss. See how long it will take to reach your goal weight with a safe, sustainable deficit.

Macro Calculator

Calculate your ideal daily macros (protein, carbs, fat) based on your body stats, activity level, and goal - weight loss, maintenance, or muscle gain.

Disclaimer

This calculator provides estimates for informational purposes only and should not be considered medical advice. Individual results may vary based on factors not captured by these formulas. Consult a healthcare professional before making changes to your diet or exercise routine, especially if you have any existing health conditions.