How many extra calories do I need while breastfeeding?

Exclusive breastfeeding typically requires an additional 2,000-2,500 kJ (500-600 kcal) per day. If you are partially breastfeeding (supplementing with formula or baby is eating solids), about 1,000-1,250 kJ (250-300 kcal) extra per day is sufficient. These figures come from the NHMRC Australian Dietary Guidelines.

Can I diet while breastfeeding?

Gentle weight loss of up to 0.5 kg per week is generally safe while breastfeeding, as long as you eat at least 7,100 kJ (1,700 kcal) per day. Avoid very low calorie diets as they can reduce milk supply and deplete your nutrient stores. Always consult your doctor or an Accredited Practising Dietitian before dieting while breastfeeding.

Will eating less affect my milk supply?

Mild calorie restriction (up to 2,000 kJ deficit per day) generally does not affect milk supply for well-nourished women. However, severe calorie restriction, crash diets, or dehydration can reduce milk production. Stay well hydrated and ensure adequate nutrition, particularly calcium, iron, and omega-3 fatty acids.

When can I start trying to lose pregnancy weight?

Most health professionals recommend waiting at least 6-8 weeks after delivery before actively trying to lose weight, and longer if you had a caesarean section. In the early weeks, focus on recovery, bonding, and establishing your milk supply. Gradual weight loss starting from 2-3 months postpartum is safe for most women.

Breastfeeding Calorie Calculator

Breastfeeding increases your daily energy needs by 2,000-2,500 kJ (500-600 kcal) per day. This calculator helps you determine your total daily calorie needs during lactation, accounting for whether you are exclusively breastfeeding or combining with formula.

Enter Your Details

Age

years

Weight

Height

Activity Level

Breastfeeding Type

Trying to Lose Weight?

How It Works

Your baseline TDEE is calculated using the Mifflin-St Jeor equation and activity factor. An additional 500 kcal (2,090 kJ) per day is added for exclusive breastfeeding, or 250 kcal (1,045 kJ) for partial breastfeeding (combining with formula or solids). If you are also trying to lose pregnancy weight, a gentle deficit of no more than 500 kcal below your lactation TDEE is applied.

Quick Reference

Profile	Base TDEE	BF Type	Extra	Total Needs
55 kg, sedentary	6,150 kJ	Exclusive	+2,090 kJ	8,240 kJ
60 kg, light	7,070 kJ	Exclusive	+2,090 kJ	9,160 kJ
65 kg, moderate	8,010 kJ	Exclusive	+2,090 kJ	10,100 kJ
70 kg, light	7,490 kJ	Exclusive	+2,090 kJ	9,580 kJ
75 kg, moderate	8,440 kJ	Exclusive	+2,090 kJ	10,530 kJ
60 kg, light	7,070 kJ	Partial	+1,045 kJ	8,115 kJ
65 kg, moderate	8,010 kJ	Partial	+1,045 kJ	9,055 kJ
70 kg, light	7,490 kJ	Partial	+1,045 kJ	8,535 kJ
75 kg, moderate	8,440 kJ	Partial	+1,045 kJ	9,485 kJ
80 kg, active	9,860 kJ	Partial	+1,045 kJ	10,905 kJ

All profiles assume female, age 30, average height 165 cm. Extra energy based on NHMRC recommendations.

Frequently Asked Questions

How many extra calories do I need while breastfeeding?: Exclusive breastfeeding typically requires an additional 2,000-2,500 kJ (500-600 kcal) per day. If you are partially breastfeeding (supplementing with formula or baby is eating solids), about 1,000-1,250 kJ (250-300 kcal) extra per day is sufficient. These figures come from the NHMRC Australian Dietary Guidelines.
Can I diet while breastfeeding?: Gentle weight loss of up to 0.5 kg per week is generally safe while breastfeeding, as long as you eat at least 7,100 kJ (1,700 kcal) per day. Avoid very low calorie diets as they can reduce milk supply and deplete your nutrient stores. Always consult your doctor or an Accredited Practising Dietitian before dieting while breastfeeding.
Will eating less affect my milk supply?: Mild calorie restriction (up to 2,000 kJ deficit per day) generally does not affect milk supply for well-nourished women. However, severe calorie restriction, crash diets, or dehydration can reduce milk production. Stay well hydrated and ensure adequate nutrition, particularly calcium, iron, and omega-3 fatty acids.
When can I start trying to lose pregnancy weight?: Most health professionals recommend waiting at least 6-8 weeks after delivery before actively trying to lose weight, and longer if you had a caesarean section. In the early weeks, focus on recovery, bonding, and establishing your milk supply. Gradual weight loss starting from 2-3 months postpartum is safe for most women.

How This Is Calculated

Baseline TDEE = BMR (Mifflin-St Jeor) × Activity Factor Exclusive Breastfeeding: +500 kcal (+2,090 kJ) per day Partial Breastfeeding: +250 kcal (+1,045 kJ) per day Lactation TDEE = Baseline TDEE + Breastfeeding Addition Weight Loss Target = Lactation TDEE − 500 kcal (minimum 1,700 kcal)

+500 kcal: = Additional energy for exclusive breastfeeding (NHMRC guideline)
+250 kcal: = Additional energy for partial breastfeeding
1,700 kcal: = Minimum safe intake while breastfeeding (7,100 kJ)

Energy needs during lactation are based on the Australian NHMRC Nutrient Reference Values. Individual needs vary depending on milk production, baby's age, and whether you are breastfeeding one or more babies.

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 Calculator

Calculate how many calories and kilojoules you need per day to lose, maintain, or gain weight. Personalised to your body and activity level.

Pregnancy Weight Gain Calculator

Calculate healthy weight gain targets during pregnancy based on your pre-pregnancy BMI. Follows Australian clinical guidelines.

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.