Donation frequency: Every 112 days, up to 3 times/year* You must be in good health and feeling well** Male donors + must be at least 17 years old in most states, at least 5’1″ tall and weigh at least 130 lbs; Female donors + must be at least 19 years old, at least 5’5″ tall and weigh at least 150 lbs; See additional requirements for student donors >>

https://www.redcrossblood.org/donate-blood/how-to-donate/eligibility-requirements.html