What this calculator does
Breastfeeding extra calorie needs works out extra daily calories needed while exclusively breastfeeding, on top of your baseline TDEE. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaBMR (Mifflin-St Jeor) × activity multiplier, plus 330 kcal/day (first 6 months) or 400 kcal/day (after 6 months) for lactation
The inputs explained
| Field | What to enter |
|---|---|
| Age (years) | A number, measured in years. Starts at 30. |
| Weight (kg) | A number, measured in kg. Starts at 65. |
| Height (cm) | A number, measured in cm. Starts at 165. |
| Activity level | Choose from Sedentary (little/no exercise), Light activity (1-3 days/week), Moderate activity (3-5 days/week), Very active (6-7 days/week), Extremely active. |
| Breastfeeding stage | Choose from First 6 months (+330 kcal/day), After 6 months (+400 kcal/day). |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with age
Every other input is held at the calculator’s starting values while age varies. Select any row to load that scenario into the calculator.
How the answer changes with age
| Age (years) | Daily calorie needs while breastfeeding | Baseline TDEE (no lactation) | Extra for breastfeeding |
|---|---|---|---|
| 15 | 2,317 kcal/day | 1,987 kcal/day | +330 kcal/day |
| 22.5 | 2,266 kcal/day | 1,936 kcal/day | +330 kcal/day |
| 30 | 2,214 kcal/day | 1,884 kcal/day | +330 kcal/day |
| 45 | 2,111 kcal/day | 1,781 kcal/day | +330 kcal/day |
| 60 | 2,008 kcal/day | 1,678 kcal/day | +330 kcal/day |
| 90 | 1,802 kcal/day | 1,472 kcal/day | +330 kcal/day |