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About this tool
Trimester-adjusted daily water target from EFSA adequate intakes, split into evenly spaced servings with a bedtime cut-off.
This calculator gives a daily fluid target for pregnancy and turns it into a timed drinking schedule. It starts from EFSA's Adequate Intake of 2.0 litres of total water a day for adult women (or 35 ml per kg if you prefer a weight-based baseline), then adds a trimester increment derived from the extra energy requirement of pregnancy — about 70 kcal a day in the first trimester, 260 in the second and 500 in the third — converted at roughly 1 ml of water per kcal. Because around 20% of total water comes from food, the drinks target shown is 80% of the total.
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Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
Uses the EFSA adequate intake for water rather than the folklore eight-glasses rule.
Scales the increment with the energy cost of each stage instead of one flat number for nine months.
Splits the day into evenly timed servings with a bedtime cut-off to reduce night waking.
EFSA sets the adequate intake for pregnancy at 2.3 litres of total water a day — the 2.0 litres for adult women plus 300 ml. Roughly 20% of that comes from food, so about 1.8 litres a day as drinks, more in hot weather or with regular exercise.
Yes, gradually. Extra energy requirements rise from about 70 kcal a day in the first trimester to 500 kcal a day in the third, and water needs track energy at roughly 1 ml per kcal, so the third trimester needs a few hundred millilitres a day more than the first.
Mild ankle and foot swelling is common and is not caused by drinking too much; staying well hydrated with normal salt intake is generally advised. Sudden swelling of the face or hands, or swelling with headache or visual changes, needs same-day medical review as it can signal pre-eclampsia.
Yes. Sustained intakes far above need can dilute blood sodium, and healthy kidneys clear only about 0.8-1.0 litres of free water an hour. If your plan calls for more than about 4 litres of drinks a day, or you have kidney, heart or blood-pressure conditions or severe vomiting, discuss the target with your midwife or doctor. This tool is informational and does not replace antenatal care.
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