Convert GMT to KST
See the 9-hour time difference, compare hours side by side, and schedule meetings between GMT and Korea Standard Time.
How GMT Converts to KST
KST is UTC+9, so it is 9 hours ahead of GMT year-round. Enter any GMT time to see the matching Korea Standard Time instantly.
Hour-by-Hour Time Table
Use the visual comparison grid and hourly table to match GMT hours with KST at a glance. Export selected times with ICS download or send to Google Calendar and Gmail.
Schedule Meetings Accurately
Plan calls between GMT and KST with automatic timezone handling and historical offset tracking. Data is based on the IANA timezone database for reliable DST and rule updates.
How to Convert GMT to KST
Open the GMT to KST page: Go to https://www.xconvert.com/time-converter/gmt-to-kst-converter. The page opens with GMT and KST already set up in the comparison grid, which is useful when you are scheduling a call between London-based teams using GMT and partners in Seoul working on Korea Standard Time.
Add comparison cities if your schedule involves more teams: Click + Add City and search for cities that matter to your workflow, such as London for UK operations, Seoul for South Korean headquarters, or Accra if you coordinate with West African teams that also use GMT. This is especially helpful for industries like electronics, gaming, shipping, and international sales, where a GMT-based office may need to line up handoffs with South Korean teams.
Select the meeting window on the grid: Click Select to enter selection mode, then drag across the colored timeline on the GMT row to highlight a time range in purple. For example, dragging from 9:00 GMT to 12:00 GMT shows the matching 18:00 KST to 21:00 KST, while 15:00 GMT lines up with 0:00 KST the next day, making it easy to see when an afternoon GMT meeting pushes into late-night hours in Korea.
Export and share the confirmed time: After selecting a range, use the export options shown on the page: ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. This is practical when a UK client team wants to send a confirmed call slot to colleagues in South Korea so everyone receives the meeting in their own local calendar without manually converting GMT to KST.
Understanding the GMT to KST Time Difference
GMT is UTC+0 and KST is UTC+9, so KST is 9 hours ahead of GMT. In practical terms, when it is 9:00 GMT, it is 18:00 KST, and when it is 12:00 GMT, it is 21:00 KST, which places Korean local time well into the evening during a standard GMT business morning.
The difference becomes even more important later in the GMT day because 15:00 GMT = 0:00 KST the next day and 18:00 GMT = 3:00 KST the next day. That next-day rollover matters for remote teams, customer support coverage, and travel planning, because a same-day afternoon call in a GMT country can already be after midnight in South Korea.
GMT is a standard-time abbreviation, and its DST counterpart is IST, while KST does not observe DST. That means the GMT to KST relationship is stable when both are being compared as listed here, but seasonal clock changes in places that move away from standard GMT can affect real-world scheduling in some months, so teams in the United Kingdom and Ireland should pay close attention to whether they are working on GMT or a daylight-saving schedule.
GMT is used across countries including the United Kingdom, Ireland, Ghana, Iceland, Senegal, Sierra Leone, Liberia, Guinea, Guinea-Bissau, Mali, Mauritania, Togo, Gambia, Burkina Faso, Ivory Coast, Sao Tome and Principe, Saint Helena, Guernsey, Jersey, and the Isle of Man. KST is used in South Korea and North Korea, making this conversion especially relevant for trade, manufacturing coordination, software releases, and media scheduling between East Asia and GMT-based regions.
Best Times for Calls and Meetings Between GMT and KST
Because KST is 9 hours ahead of GMT, the most workable meeting window usually comes from the GMT morning, which becomes KST evening. The clearest examples are 9:00 GMT = 18:00 KST and 12:00 GMT = 21:00 KST, so a GMT morning meeting can still reach South Korean teams before the end of their evening.
This makes the 9:00 GMT to 12:00 GMT range one of the most practical windows for live calls, project reviews, and cross-border client updates. It is particularly useful for companies coordinating between UK business hours and South Korean offices in sectors such as semiconductors, automotive supply chains, online gaming, consumer electronics, and international logistics.
After that window, scheduling becomes much harder because 15:00 GMT = 0:00 KST the next day and 18:00 GMT = 3:00 KST the next day. A mid-afternoon GMT meeting may already require Korean participants to join at midnight, which is usually unsuitable except for urgent incident response, production outages, or launch-night operations.
If you need recurring meetings, the visual grid helps you identify whether a slot stays inside acceptable work hours or slips into evening and overnight time in Korea. For distributed teams, this is valuable when balancing a London-side workday with Seoul-based engineering, procurement, or regional management teams that need predictable attendance.
Frequently Asked Questions
What is the time difference between GMT and KST?
KST is 9 hours ahead of GMT. Since GMT is UTC+0 and KST is UTC+9, a time shown in Korea Standard Time will always be nine hours later than the corresponding GMT time on this converter.
When is 9 AM GMT in KST?
9:00 GMT = 18:00 KST. That means a 9 AM meeting in a GMT location lands at 6 PM in South Korea, which is often still possible for business calls but already near the end of the local workday.
When is 12 PM GMT in KST?
12:00 GMT = 21:00 KST. This is a late-evening time in Korea, so it may work for occasional client calls or executive check-ins, but it is usually too late for routine daily meetings.
What happens to KST when it is 3 PM GMT?
15:00 GMT = 0:00 KST the next day. This next-day shift is important because a normal afternoon slot in GMT becomes midnight in Korea, which can easily cause confusion if teams do not notice the date change.
What time is 6 PM GMT in KST?
18:00 GMT = 3:00 KST the next day. That is deep overnight time in South Korea, so it is generally only realistic for emergency coordination, maintenance windows, or round-the-clock operational teams.
Does the difference between GMT and KST change during DST?
GMT is a standard-time abbreviation, and its DST counterpart is IST, while KST does not observe DST. As a result, KST itself stays fixed all year, but organizations in places like the United Kingdom need to be careful during months when local clocks are not on standard GMT, because business schedules may no longer match a pure GMT-to-KST comparison.
What is the best meeting time between GMT and KST?
The most practical range is usually 9:00 GMT to 12:00 GMT, which corresponds to 18:00 KST to 21:00 KST. This window allows GMT-based teams to meet during the morning while Korean participants can still join in the evening, making it one of the few workable overlaps for regular cross-border communication.
Which countries use GMT and which countries use KST?
GMT is used in countries and territories including the United Kingdom, Ireland, Ghana, Iceland, Senegal, Sierra Leone, Liberia, Guinea, Guinea-Bissau, Mali, Mauritania, Togo, Gambia, Burkina Faso, Ivory Coast, Sao Tome and Principe, Saint Helena, Guernsey, Jersey, and the Isle of Man. KST is used in South Korea and North Korea, so this conversion is especially relevant for travel, trade, and remote collaboration between East Asia and GMT-based regions.