Free Breastfeeding Calculators and Tools

Our free breastfeeding calculators give you quick, sourced answers to the questions that come up every day: how much to eat, how much milk to put in a bottle and whether the milk in the fridge is still good. Every calculator works in your browser, stores nothing and explains its formula, with worked examples and sources below it.

Our calculators

• Breastfeeding calorie calculator: estimates your daily calorie needs while nursing or pumping, using your size, activity level and how much your baby breastfeeds, plus a safe target for gradual weight loss.
• Breast milk feeding chart and calculator: shows how much breast milk babies typically drink per feed and per day, from the first days to 6 months. Handy for bottle-feeding pumped milk and packing for daycare.
• Breast milk storage calculator: tells you the exact date and time to use pumped or thawed milk by, based on CDC storage guidelines for the room, cooler, fridge and freezer.
• Baby poop color chart: pick the color in the diaper to see what it means and when to call the pediatrician, plus how many wet and dirty diapers to expect by age.
• Flange size calculator: turns your nipple measurement into a starting breast pump flange size for each side, with the signs of a good fit.
• Breastfeeding alcohol calculator: estimates when alcohol should be out of your breast milk, based on your weight and drinks and the CDC’s 2-hour guideline.

How we build our tools

Each calculator follows published guidance: the CDC for milk storage and diaper counts, the Cleveland Clinic and NIH for stool colors, the Cleveland Clinic for flange fit, published alcohol-clearance research and the CDC for alcohol, the Academy of Breastfeeding Medicine and peer-reviewed research for milk intake, and the National Academies’ energy requirements for calories. We list the sources on every tool page and check every calculation against worked examples. The results are general information for healthy, full-term babies and healthy adults. They don’t replace advice from your pediatrician, doctor or lactation consultant.