What are maintenance kilojoules?

Maintenance kilojoules (or maintenance calories) is the amount of energy you need each day to maintain your current weight. Eating above this leads to weight gain; eating below leads to weight loss.

How do I find my maintenance kJ?

Use this calculator for an estimate based on the Harris-Benedict formula. For a more precise figure, track your food intake and weight for 2-3 weeks. If your weight stays stable, your average daily intake is your maintenance level.

Should I eat at maintenance to build muscle?

For muscle building, most people eat slightly above maintenance (a surplus of 1,000-2,000 kJ per day) while following a strength training program. Beginners can sometimes build muscle at maintenance or even in a slight deficit.

Maintenance kJ Calculator

Your maintenance kilojoules is the amount of energy you need to eat each day to keep your weight stable - not gaining or losing. This is the starting point for any weight management plan.

Enter Your Details

Gender

Age

years

Weight

Height

Activity Level

How It Works

Maintenance energy is calculated using the Harris-Benedict formula for BMR, multiplied by your activity level factor. This gives your Total Daily Energy Expenditure (TDEE) - the kJ you need to maintain weight.

Quick Reference

Activity Level	Multiplier	kJ/day	kcal/day
Sedentary	×1.20	9,088	2,172
Lightly Active	×1.375	10,416	2,490
Moderately Active	×1.55	11,738	2,806
Active	×1.725	13,063	3,122
Very Active	×1.90	14,390	3,440

Example: 80 kg male, 175 cm, age 35.

How This Is Calculated

Maintenance kJ = BMR × activity multiplier

BMR: = Basal Metabolic Rate (Harris-Benedict revised equation)
Activity multiplier: = 1.2 (sedentary) to 1.9 (very active)

Your maintenance kJ is the energy you need to keep your weight stable. Eating above this leads to weight gain; eating below leads to weight loss.

Frequently Asked Questions

What are maintenance kilojoules?: Maintenance kilojoules (or maintenance calories) is the amount of energy you need each day to maintain your current weight. Eating above this leads to weight gain; eating below leads to weight loss.
How do I find my maintenance kJ?: Use this calculator for an estimate based on the Harris-Benedict formula. For a more precise figure, track your food intake and weight for 2-3 weeks. If your weight stays stable, your average daily intake is your maintenance level.
Should I eat at maintenance to build muscle?: For muscle building, most people eat slightly above maintenance (a surplus of 1,000-2,000 kJ per day) while following a strength training program. Beginners can sometimes build muscle at maintenance or even in a slight deficit.

Related Tools

Daily Energy Needs Calculator

Calculate your daily energy requirement in kilojoules using the Harris-Benedict formula based on age, weight, height, and activity level.

kJ Per Day to Lose Weight Calculator

Calculate how many kilojoules per day you should eat to lose weight at a safe, sustainable rate.

Kilojoule Deficit Calculator

Calculate your daily kilojoule deficit and see how it translates to weekly weight loss. Plan your energy balance.