How much magnesium per day? This free guide shows the recommended daily intake and safe supplement upper limit by age and sex — general reference information, not a treatment dose for deficiency.
⚠ Informational only — this shows general recommended daily intake and the safe supplemental upper limit. It is not a treatment dose. Correcting low magnesium needs a doctor’s guidance, and high-dose magnesium can be dangerous — especially with kidney problems. Don’t exceed the supplemental upper limit without medical advice.
Who is this for?
Values follow widely used reference intakes (IOM/NIH) for healthy people. The upper limit is for magnesium from supplements, not from food and water.
Recommended daily intake
— mg/day
Select an age or life stage
Supplement upper limit
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Group
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General guidance for healthy people. Most magnesium should come from food (greens, nuts, seeds, wholegrains, legumes). If you have kidney disease or take medication, talk to a doctor before supplementing.
Use this free magnesium intake guide to see the recommended daily amount and safe supplement upper limit for your age and sex. It shows general reference intakes — not a treatment dose for a deficiency, which needs a doctor.
Important: this tool shows general recommended intake and the safe supplemental upper limit for healthy people. It is not a dose to correct a deficiency. High-dose magnesium can be dangerous — particularly if you have kidney problems, since the body can’t clear the excess. Don’t exceed the supplement upper limit or start high-dose magnesium without medical advice.
What this magnesium guide shows you
This magnesium intake guide shows the recommended daily amount for your age, sex and life stage, plus the upper limit for supplemental magnesium — the most that’s considered safe from supplements and magnesium-containing medicines. Most of your magnesium should come from food.
Recommended daily magnesium
Age / stage
Male
Female
1–3 years
80 mg
80 mg
4–8 years
130 mg
130 mg
9–13 years
240 mg
240 mg
14–18 years
410 mg
360 mg
19–30 years
400 mg
310 mg
31+ years
420 mg
320 mg
Pregnant
—
~350–360 mg
These reflect widely used reference intakes (IOM/NIH) for healthy people. Needs vary individually.
The supplement upper limit
For ages 9 and up, the tolerable upper limit for supplemental magnesium is 350 mg a day — and importantly, this applies only to magnesium from supplements and medicines, not the magnesium naturally in food and water. That’s why a recommended total intake can sit near or above 350 mg while the supplement limit stays at 350 mg.
Why deficiency treatment is different
If a blood test and assessment show you’re low in magnesium, a doctor may recommend higher doses for a time, chosen and monitored for your situation — well beyond a general supplement limit. That’s a medical decision, which is why this tool doesn’t provide treatment doses.
Good food sources of magnesium
Leafy greens like spinach.
Nuts and seeds — almonds, pumpkin seeds.
Legumes — beans, lentils.
Wholegrains and dark chocolate.
Can you take too much magnesium?
Yes. Too much supplemental magnesium commonly causes diarrhoea and cramping, and very high amounts can be dangerous — especially for people with reduced kidney function, who can’t excrete the excess. This is why the upper limit and medical guidance matter.
Magnesium FAQ
How much magnesium should I take per day?
Recommended daily intake is roughly 400–420 mg for adult men and 310–320 mg for adult women, including food. Teens and children need less. These are general reference amounts for healthy people, so check with a doctor about your own needs.
What is the upper limit for magnesium supplements?
For ages 9 and up, the tolerable upper limit for supplemental magnesium is 350 mg a day. This applies only to magnesium from supplements and medicines — not the magnesium naturally found in food and water.
Why can the recommended amount be higher than the supplement limit?
Because the recommended total intake counts food, while the 350 mg limit is for supplements only. Most of your magnesium is meant to come from food, so the two figures measure different things.
What dose treats a magnesium deficiency?
Treatment doses are higher and are chosen and monitored by a doctor based on testing and your situation. This guide doesn't provide them, because correcting a deficiency is a medical decision.
Can you take too much magnesium?
Yes. Excess supplemental magnesium commonly causes diarrhoea and cramping, and very high amounts can be dangerous — especially for people with kidney problems, who can't clear the excess. Stay within the limit unless a doctor advises otherwise.
Is the magnesium guide free to use?
Yes, this magnesium intake guide is completely free, needs no sign-up, and works instantly in your browser. It is informational only and not medical advice.
