Daily Calcium Needs Calculator

Daily calcium needs vary significantly based on age, gender, pregnancy status, and other life stage factors. The figures here are the recommended dietary allowances set by the Institute of Medicine (IOM, now the National Academy of Medicine) in 2011 and published by the National Institutes of Health (NIH).
This page gives the target. To add up what you actually eat against it, use the Calcium Intake Calculator.

Recommended Daily Allowances (RDA) by age group:

• Children 1-3 years: 700 mg per day
• Children 4-8 years: 1,000 mg per day
• Children 9-13 years: 1,300 mg per day
• Teens 14-18 years: 1,300 mg per day
• Adults 19-50 years: 1,000 mg per day
• Women 51-70 years: 1,200 mg per day
• Men 51-70 years: 1,000 mg per day
• Adults 71+ years: 1,200 mg per day
• Pregnant or breastfeeding teens: 1,300 mg per day
• Pregnant or breastfeeding adults: 1,000 mg per day

Why calcium matters:

Calcium is the most abundant mineral in the human body. About 99% of calcium is stored in bones and teeth, where it provides structural support. The remaining 1% is found in blood, muscles, and other tissues where it plays critical roles in nerve transmission, muscle contraction, and blood clotting.

Things that change how far your calcium goes:

• Low vitamin D levels reduce calcium absorption from food
• Caffeine costs less than its reputation. Heaney’s 2002 review put it at about 2 to 3 mg of calcium per cup of coffee, which a tablespoon or two of milk replaces
• High sodium diets cause more calcium to be lost through urine
• Certain medications like corticosteroids can interfere with calcium metabolism

Pregnancy and breastfeeding, perhaps surprisingly, do not raise the target. The body absorbs calcium more efficiently in pregnancy, so the allowance stays at what it is for anyone the same age.

Food sources of calcium:

Dairy products like milk, cheese, and yogurt are well-known calcium sources. Non-dairy options include fortified plant milks, leafy greens like kale and broccoli, canned sardines with bones, tofu made with calcium sulfate, and almonds.

Upper intake limit: The tolerable upper intake level, food and supplements together, is 2,500 mg a day for children 1 to 8 and adults 19 to 50, 3,000 mg for ages 9 to 18, and 2,000 mg from 51. Exceeding it over long periods may increase the risk of kidney stones, and whether high-dose supplements affect heart risk is still argued over.