Water Intake During Pregnancy
Growing a baby means growing your fluid budget. Calculate a target built on your pre-pregnancy weight with a +300 ml pregnancy adjustment built in.
Fill in your details to see your daily goal
Why Hydration Matters More Now
Pregnancy is the most dramatic fluid-balance project your body will ever run. Blood volume rises by 40–50% to supply the placenta; amniotic fluid — which the fetus both swallows and excretes — turns over completely every few hours; and your kidneys are processing waste for two. Falling short is linked to fatigue, constipation, Braxton Hicks irritability and, in later pregnancy, a higher risk of low amniotic fluid. The calculator above starts from your pre-pregnancy weight and adds a 300 ml pregnancy allowance, in line with mainstream prenatal nutrition guidance — during breastfeeding, increase that adjustment to roughly 700 ml.
Practical anchors: one glass on waking (overnight losses are higher in pregnancy), a glass with every snack and meal, and a bottle at every prenatal appointment. If morning sickness makes plain water unappealing, ice chips, diluted juice and sparkling water all count.
Frequently Asked Questions
How much water should I drink during pregnancy?
Most guidance suggests about 2.3–3 liters of total fluid daily during pregnancy, roughly 300 ml above your non-pregnant target. Use your pre-pregnancy weight in the calculator above — it already includes the pregnancy adjustment.
Why does pregnancy increase fluid needs?
By the third trimester your blood volume has expanded by nearly 50%, you're building amniotic fluid, and you're supporting a placenta and a growing baby. Each of those demands extra fluid on top of your baseline needs.
Does breastfeeding need even more water?
Yes — lactation typically adds around 700 ml per day on top of your baseline, since breast milk is about 87% water. Keep a glass of water at every feeding spot as the simplest rule of thumb, and always confirm targets with your prenatal care team.
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