Free tool
Estimates BMR with the Schofield equation — the equation Eat For Health uses — then applies a physical activity level for total energy, with protein and fluid alongside. Results in kilojoules and calories. Nothing you type leaves your browser.
Schofield publishes separate coefficients by sex.
Daily energy target
1,980 kcal/day · 118 kJ/kg
Protein
58.8 g
0.84 g/kg
Fluid
2,100 mL
30 mL/kg
Working
A predicted figure is a starting point, not a prescription. Predictive equations carry meaningful individual error and are least reliable at extremes of body composition, in critical illness and in obesity. Titrate against measured weight change and clinical response, and apply professional judgement. This tool is intended for use by qualified practitioners.
The formula
BMR (MJ/day) = (slope × weight in kg) + intercept — coefficients by sex and age band, below
BMR (kJ/day) = BMR in MJ × 1000
Energy requirement = BMR × physical activity level
Protein (g/day) = protein factor in g/kg × weight in kg
Fluid (mL/day) = fluid factor in mL/kg × weight in kg
Calories are derived, not calculated separately: kcal = kJ ÷ 4.184
The Schofield equation predicts basal metabolic rate from body weight, using different coefficients for each sex and age band. It was published in 1985 in megajoules per day, adopted by the World Health Organization, and is the equation behind the Eat For Health estimated energy requirement figures. Because the calculation is done in MJ and converted once at the end, the kilojoule and calorie figures can never disagree with each other.
Nothing else is applied. There is no stress factor, no injury factor, no adjustment for body composition, and no smoothing between age bands — a patient who turns 30 moves from one row of the table to the next, and the number steps accordingly. The result panel shows the full working with your numbers substituted so you can check it by hand.
Weight is used exactly as entered. If you would normally calculate on ideal or adjusted body weight, enter that figure instead — this tool does not derive it for you.
| Age band | Female (MJ/day) | Male (MJ/day) |
|---|---|---|
| 3–9 years | 0.085W + 2.033 | 0.095W + 2.11 |
| 10–17 years | 0.056W + 2.898 | 0.074W + 2.754 |
| 18–29 years | 0.062W + 2.036 | 0.063W + 2.896 |
| 30–59 years | 0.034W + 3.538 | 0.048W + 3.653 |
| 60+ years | 0.038W + 2.755 | 0.049W + 2.459 |
W = body weight in kilograms. Result in megajoules per day.
The Schofield equation estimates basal metabolic rate (BMR) from body weight, age band and sex. It was published in 1985, adopted by the World Health Organization, and is the equation used by Eat For Health to estimate energy requirements in Australia and New Zealand. Multiplying BMR by a physical activity level gives an estimated total energy requirement.
Both. The Schofield equations were published in megajoules per day, so the calculation is done in MJ and converted, which means the kilojoule and calorie figures always agree. Kilojoules are the working unit in Australian practice and the unit required on Australian food labels.
Predictive equations estimate group averages well and individuals less well — error against indirect calorimetry is commonly around 10 to 20 per cent for any given person, and is larger at extremes of body composition, in critical illness and in obesity. Use the result as a starting point and titrate against measured response.
Predictive equations perform poorly in infants and very young children, where growth, feeding method and clinical context dominate requirements. That assessment belongs with a paediatric dietitian rather than a public web form.
The calculator inside Cladiv works from ideal and adjusted body weight as well as actual weight, takes energy and protein as kcal/kg and g/kg factors with condition-specific reference ranges, and distributes the result into protein, carbohydrate, fat and fibre targets that feed straight into a meal plan.
Yes. It runs entirely in your browser, nothing you enter is transmitted or stored, and no account is required.
Inside Cladiv the same calculation works from adjusted body weight, takes condition-specific energy and protein ranges, and distributes the result into protein, carbohydrate, fat and fibre targets that feed straight into a meal plan built on FSANZ food composition data — with a shopping list, instead of a number you retype.