Key takeaways: At 12 months, formula-fed babies can switch to whole cow’s milk, about 16 to 24 ounces a day. Too much milk can lead to iron deficiency. Serve milk in a cup. Breastfeeding can continue as long as you both want.
Your baby’s first birthday brings a big feeding change: for many families, it’s time to switch from formula to milk.
When to Switch
Around 12 months, babies who have been on formula can switch to plain, pasteurized whole cow’s milk. Toddler formulas aren’t necessary.
How Much Milk?
About 16 to 24 ounces (2 to 3 cups) a day for children 12 to 24 months. More than this can:
- Fill your toddler up so they eat less food.
- Reduce iron absorption and contribute to iron deficiency anemia.
- Cause constipation.
Whole Milk or Lower Fat?
Healthy Eating Research and the AAP have recommended whole milk for most children 12 to 24 months. The 2025-2030 Dietary Guidelines for Americans say that dairy with different fat levels can fit into a healthy eating pattern. If your child has risk factors such as obesity or a family history of heart disease, your doctor may advise differently. Ask your pediatrician what’s right for your child.
How to Make the Switch
- Cold turkey: many toddlers accept whole milk right away.
- Gradual: mix formula (or breast milk) with whole milk, gradually increasing the proportion of milk over 1 to 2 weeks.
- Warm it slightly if your toddler is used to warm bottles.
- Serve in a cup, not a bottle, ideally with meals and snacks.
Breastfeeding After 12 Months
The AAP supports breastfeeding for 2 years or beyond, as long as mutually desired. Breastfed toddlers who are eating a varied diet may not need cow’s milk. Ask your doctor about vitamin D and other nutrients.
Plant-Based Milks
Most plant-based milks, like almond, oat, rice, and coconut milk, are low in protein and other nutrients. Unsweetened, fortified soy milk is the only plant milk considered nutritionally similar to cow’s milk. If your child can’t have cow’s milk, talk to your doctor or a dietitian.
Food First
After 12 months, food becomes the main source of nutrition. Offer three meals and two snacks a day with a variety of foods, including iron-rich foods.
Vitamin D
Children who drink 16 to 24 ounces of vitamin D-fortified milk daily usually get enough. Others may need a supplement.
Call your toddler’s doctor if: your child has hives, vomiting, diarrhea, or blood in the stool after drinking milk, refuses most foods, or seems pale and tired (possible signs of anemia).
The Bottom Line
At 12 months, formula-fed babies can switch to whole milk: 16 to 24 ounces a day, in a cup. Too much milk can crowd out iron-rich foods. Breastfeeding can continue as long as you both want.
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Sources
- Healthy Eating Research. Healthy beverage consumption in early childhood: recommendations from key national health and nutrition organizations. 2019. https://healthyeatingresearch.org
- Baker RD, Greer FR; Committee on Nutrition. Diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatrics. 2010;126(5):1040-1050.
- US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. Released January 2026. https://www.dietaryguidelines.gov
- Meek JY, Noble L; Section on Breastfeeding. Policy statement: breastfeeding and the use of human milk. Pediatrics. 2022;150(1):e2022057988.
- Wagner CL, Greer FR; Section on Breastfeeding; Committee on Nutrition. Prevention of rickets and vitamin D deficiency in infants, children, and adolescents. Pediatrics. 2008;122(5):1142-1152.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
