Blood Donation Interval Calculator

Overview

Enter the date and type of your last blood donation to see when you can donate again and how many days are left. In Korea the waiting period is set by the donation you just gave, not the one you plan to give: 8 weeks (56 days) after whole blood and 2 weeks (14 days) after any apheresis donation. The calculator also checks age and weight eligibility and how many donations you have left in the past 12 months.

Formula

Next eligible date = last donation date + interval for the last donation type
· After whole blood (320mL or 400mL) → 56 days (8 weeks)
· After plasma, platelet, or platelet-plasma apheresis → 14 days (2 weeks)
Days remaining = next eligible date − today
Annual allowance left = limit − donations in the past 12 months (whole blood 5, platelet + platelet-plasma combined 24, plasma apheresis unlimited)

How to Use

1. 1Enter the date of your last donation, which appears on your donation certificate or in the Korean Red Cross RedConnect app.
2. 2Select the type you donated last — this determines the 56-day or 14-day interval.
3. 3Select the type you plan to donate next, which determines the age, weight, and annual-limit checks.
4. 4Enter sex, age, and body weight to check the eligibility thresholds.
5. 5Enter your whole blood and platelet-type donation counts for the past 12 months to see the remaining allowance.

Examples

Background

The intervals and thresholds follow the Korean Blood Management Act enforcement rules (Annex 1-2, donor deferral criteria) and the Korean Red Cross Blood Services standards published at bloodinfo.net. Whole blood carries the long 8-week gap because the red cells and iron stores removed in one collection take weeks to rebuild, whereas apheresis separates only plasma or platelets and returns the red cells, which is why a 2-week gap is considered safe. The same reasoning sets the volume-specific minimum ages (16 for 320mL, 17 for 400mL), the upper age of 59 for platelet-type apheresis, and the hemoglobin thresholds of 12.5 g/dL for whole blood and 12.0 g/dL for apheresis.

Tips

• ✔The Korean Red Cross RedConnect app stores your donation history, so check it there if you cannot recall the exact date.
• ✔Plasma apheresis has no annual cap, so with only a two-week gap it is the type you can give most often.
• ✔You cannot shorten the wait by switching types: after whole blood you wait 8 weeks even if your next donation is apheresis.
• ✔Sleeping well the night before and drinking plenty of fluids on the day reduces the chance of being deferred at the on-site hemoglobin and blood pressure check.
• ✔Donors aged 65 and over may donate only if they donated before turning 65, so keeping your history unbroken through your sixties matters.

FAQ