How to use
Enter the enlistment date (the call-up date for social service agents) and choose the type of service; the result appears. It shows the estimated discharge date, the D-day countdown to discharge, service progress (%), days served, days left and total days of service, the dates when service progress reaches 25, 50, 75 and 100%. “Today” is the date on your device.
Before enlistment the result counts down to enlistment; on the discharge date it shows “Discharge day”, and after discharge it counts the days since discharge. If you know your length of service in months, or have days not counted as service or an extension, open Adjustments and enter them. A number of months entered there replaces the value calculated from the enlistment date.
Length of service by branch
The table distinguishes current service terms from statutory periods. Active-duty terms reflect adjustments under Article 19 of the Military Service Act; social service agents and full-time reservists follow the rules of their respective systems.
| Type of service | Current length | Statutory length | Legal basis |
|---|---|---|---|
| Army / Marine Corps (incl. KATUSA) | 18 months | 2 years | Military Service Act, Art. 18(2) |
| Navy | 20 months | 2 years 2 months | Military Service Act, Art. 18(2) |
| Air Force | 21 months | 2 years 3 months | Military Service Act, Art. 18(2) |
| Social service agent | 21 months | 2 years 2 months | Military Service Act, Art. 30(1) |
| Full-time reservist | 18 months | Up to 2 years 6 months | Military Service Act, Art. 23(1); Enforcement Decree, Art. 37(2) |
Conscripted police, maritime police and firefighting services have been abolished and are not included. Industrial technical personnel and expert researchers use different start dates and counting rules, so this calculator does not cover them.
The 2018 reduction and how the enlistment date is used
Under the 2018 Defense Reform 2.0, enlisted service was cut by 3 months (90 days). The cut was not made all at once: starting from a set enlistment date, the discharge date moved one day earlier for every 2 weeks (14 days) of later enlistment. So two Army soldiers can serve a different number of days depending on when they enlisted. The calculator uses the enlistment date to pick the length of service that applied at the time.
| Type of service | Before | Current | Reduction starts (enlistment) | Full 90 days reached (last enlistment) |
|---|---|---|---|---|
| Army / Marine Corps / full-time reservist | 21 months | 18 months | January 3, 2017 | June 15, 2020 |
| Navy | 23 months | 20 months | November 3, 2016 | April 15, 2020 |
| Air Force / social service agent | 24 months | 21 months | October 3, 2016 | March 15, 2020 |
The calculation works like this:
- Enlistment before the start date: use the length before the reduction.
- Enlistment from the start date to the last date of the reduction: reduction k = (days from the start date to the enlistment date) ÷ 14, rounded down, + 1 (1–90 days). Discharge date = end date for the length before the reduction − k days.
- Enlistment after that: use the current length.
Army examples:
| Enlistment date | Reduction | Discharge date |
|---|---|---|
| December 31, 2016 | None (21 months) | September 30, 2018 |
| January 3, 2017 | 1 day | October 1, 2018 |
| July 27, 2018 | 41 days | March 16, 2020 |
| June 2, 2020 | 90 days | December 1, 2021 |
| June 16, 2020 | None (18 months) | December 15, 2021 |
There was also a phased reduction in 2006–2010, but its full official schedule could not be confirmed, so automatic calculation starts with enlistment on March 1, 2011. If you enlisted earlier, enter your length of service in months under Adjustments.
How the discharge date is counted
- The enlistment date is day 1 of service. It counts toward the period (Enforcement Decree of the Military Service Act, Article 27(1); Framework Act on Public Administration, Article 6(2)).
- N months of service end on the day before the same date N months later. For example, 18 months from June 2, 2020 end on December 1, 2021 (Civil Act, Article 160(2)).
- If the last month has no such date, service ends on the last day of that month (Civil Act, Article 160(3)). An Army soldier who enlisted on August 31, 2025 is discharged on February 28, 2027, because February 2027 has no 31st. The calculator applies this rule as written, so enlistment on August 29 or 30 also gives February 28. The date set by the unit may differ.
- Days not counted as service and extension days are added after the end date.
Service progress is (days served ÷ total days of service) × 100, counting both the enlistment date and today. It is a simple figure for tracking progress, not an official measure. It is rounded down to two decimal places so that it does not show 100% on the day before discharge.
For example, an Army soldier who enlisted on March 2, 2026 is discharged on September 1, 2027, for a total of 549 days. On September 28, 2026 it is day 211: D-338, with 38.43% of service done. Progress reaches 25% on July 17, 2026, 50% on December 1, 2026 and 75% on April 17, 2027.
The result truncates progress to 2 decimal places; cards with numeric progress truncate it to 1. Profile photos show progress through the fill of the D-day letters instead of a number.
Rank on the card
The default rank is calculated from the enlistment date and today. If your actual rank differs, select private, private first class, corporal or sergeant to override it. Choose From dates to restore automatic calculation. No enlisted rank is shown for social service agents.
Saving and sharing the discharge card
Below the result you can choose the card design, size, name or nickname and rank. The card shows the service type, D-day, progress bar, enlistment and discharge dates, and your selected rank.
- Design: choose Night Blue, Field Green, Black Gold, or an Army, Navy, Air Force or Marines theme. The selected design applies to the preview, saved files and copied image.
- Upload your photo: use a JPG, PNG or WebP photo (up to 10MB) as the background. Photos are center-cropped to the card ratio. You can switch between preset designs and your photo, or remove the uploaded photo.
- Size: choose Feed 4:5 (1080×1350), Story 9:16 (1080×1920), Profile photo 1:1 (1080×1080), or KakaoTalk background 9:16 (1080×1920). In profile photos, the D-day letters fill according to service progress; dates and numeric progress are omitted. The KakaoTalk background keeps roughly the bottom 40% clear for the profile. Check cropping and screen overlays when setting the image in the app.
- Rank: the date-based rank appears to the left of your name. Use the selector to override it or return to From dates.
- Name or nickname: if you enter one, it appears near the top of the card; leave it empty to hide it (up to 12 characters).
- Save PNG / Save SVG: PNG is an image for sharing on social media. SVG text and shapes stay sharp when enlarged, but the embedded background image can become blurry. The background is included in the saved SVG.
- Copy image: copies a PNG to the clipboard so you can paste it straight into a messenger or social app. If your browser cannot copy images, the button is turned off; save the PNG and upload it instead.
The preset backgrounds are AI-generated images. You can also upload your own photo. The preset designs do not use actual unit insignia or the Ministry of National Defense logo.
Uploaded photos and entered names or nicknames are not saved for your next visit. Use the save or copy buttons to keep a card on your device.