How Many Hours Is Korea Ahead of the US? Best Websites to Check Time Differences Accurately

If you’re living in South Korea or working with someone based there while you’re in the United States, the time difference can be tricky to manage. South Korea operates on Korea Standard Time (KST), which is UTC+9, while the United States spans multiple time zones, from UTC-5 (Eastern Time) to UTC-10 (Hawaii Standard Time). That means the time gap between Korea and the US can vary anywhere from 14 to 19 hours, depending on where you are in the States and whether Daylight Saving Time is active.

Luckily, several websites make it easy to compare time zones in real time. In this guide, we’ll go over reliable platforms you can use to check the current time difference between Korea and different US cities—whether you’re scheduling a business call, planning a trip, or just trying not to wake up your friend at 3 a.m.

 

Time and Date (timeanddate.com)

Time and Date is one of the most trusted websites when it comes to global time zone tracking. You can search for “Seoul” and any US city like “New York” or “Los Angeles” and see both current local times side by side.

Features:

• Real-time clocks for both cities

  
  

• Clear indication of whether Daylight Saving Time is in effect

  
  

• Built-in calendar and meeting planner

  
  

• Option to generate a table comparing multiple cities

  
  

This site is especially helpful if you’re scheduling meetings or need to know when a specific time in the US will be in Korea.

Website: https://www.timeanddate.com

World Time Buddy (worldtimebuddy.com)

World Time Buddy is a user-friendly time zone converter popular among remote workers and frequent travelers. You can add several locations on a single timeline and drag the pointer to find the best overlap time.

Features:

• Timeline view for multiple cities

  
  

• Simple drag-and-drop time selection

  
  

• Easy to check business hour overlaps

  
  

• Free and paid versions available

  
  

It’s especially helpful if you’re juggling time zones for more than two countries at once. The clean interface makes it easier to visually plan events without doing mental calculations.

Website: https://www.worldtimebuddy.com

The Time Zone Converter (thetimezoneconverter.com)

This site does one thing and does it well. The Time Zone Converter is a quick and clean tool to convert any time between two locations.

Features:

• Fast loading and easy to use

  
  

• Great mobile performance

  
  

• No signup required

  
  

Just type “10:00 AM Seoul” and choose “Los Angeles,” and it will instantly show you the corresponding time. It’s especially useful for mobile users or people who just want a quick answer.

Website: https://www.thetimezoneconverter.com

Google Search

Believe it or not, Google Search itself can be a reliable and immediate option. Typing a query like
time in Seoul or
time difference between New York and Korea
will show you the real-time clock and offset without needing to click into any websites.

While it doesn’t offer planning tools or side-by-side comparisons, it’s excellent for checking the current time quickly and accurately.

Savvy Time (savvytime.com)

Savvy Time is a lesser-known but powerful time zone converter. What makes it stand out is its clean design and built-in meeting scheduler that works well for both mobile and desktop users.

Features:

• Integrated time converter and planner

  
  

• Supports multiple cities

  
  

• Syncs with calendars

  
  

You can save favorite locations, making it faster to use if you regularly coordinate between the US and Korea.

Website: https://www.savvytime.com

Time.is

Time.is is one of the fastest-loading time zone websites on the internet. It shows you the exact current time, how accurate your system clock is, and allows you to compare any two cities instantly.

Features:

• Extremely fast and lightweight

  
  

• Minimalist design

  
  

• Accurate atomic time sync

  
  

Though it lacks some planning tools, it’s perfect for users who just want a clean, fast display of the current time in multiple cities.

Website: https://time.is

Korea vs. US Time Difference Cheat Sheet

To give you a quick reference, here’s a snapshot of how far ahead Korea is compared to major US time zones:

Note: Daylight Saving Time (DST) in the US usually begins in March and ends in November. Korea does not observe DST, so the time difference can change depending on the season.

When Is the Best Time to Schedule Meetings?

Because of the large time gap, it can be challenging to find overlapping work hours. Here’s a general guide:

• If you’re in Korea and scheduling with New York: Aim for 9 PM–11 PM KST (8 AM–10 AM EST)

  
  

• If you’re in Korea and scheduling with California: Try 6 AM–8 AM KST (1 PM–3 PM PST the previous day)

  
  

• If you’re in the US scheduling with Korea: Early morning in the US or late evening in Korea is often the sweet spot

  
  

Tools like World Time Buddy or Savvy Time help you identify these overlapping windows easily.

Why It’s Important to Double Check

Flight schedules, meeting times, visa appointments, and even virtual classes can be affected by miscalculations in time zones. It’s especially crucial to be mindful of Daylight Saving Time, which doesn’t exist in Korea. Relying on real-time tools instead of mental math or static charts can save you from showing up 12 hours late—or early.

Use Time Tools Like a Pro

If you work remotely, travel internationally, or regularly talk to friends and family overseas, it’s worth bookmarking at least two of the websites mentioned. Use one for quick lookups (like Google or Time.is) and another for detailed scheduling (like World Time Buddy or Time and Date).

Saving city pairs and getting into the habit of checking the real-time difference will help you avoid missed meetings and awkward middle-of-the-night calls. Whether you’re a digital nomad or just someone planning a phone call to Seoul, the right tools can make cross-border communication effortless.