IST to GMT converter
India Standard Time to Greenwich Mean Time. GMT is 5 h 30 min behind of IST all year.
From
IST · Kolkata GMT+5:30 · UTC+5:30
- GMT · GMTUTC · UTC+0 · 5 h 30 min behind03:30Mon, Sep 28
The gap between IST and GMT
| 2026 | IST clocks | GMT clocks | Difference |
|---|---|---|---|
| January | GMT+5:30 UTC+5:30 | UTC UTC+0 | 5 h 30 min behind |
| July | GMT+5:30 UTC+5:30 | UTC UTC+0 | 5 h 30 min behind |
Neither clock changes relative to the other, so this gap holds all year.
Convert the other way: GMT to IST · Plan a meeting across more places
IST to GMT time table
Every hour of the IST day and the matching GMT time, for a mid-January and a mid-July date (they are identical, since the gap never changes).
| IST | GMT · January |
|---|---|
| 12:00 AM | 6:30 PM (−1 day) |
| 1:00 AM | 7:30 PM (−1 day) |
| 2:00 AM | 8:30 PM (−1 day) |
| 3:00 AM | 9:30 PM (−1 day) |
| 4:00 AM | 10:30 PM (−1 day) |
| 5:00 AM | 11:30 PM (−1 day) |
| 6:00 AM | 12:30 AM |
| 7:00 AM | 1:30 AM |
| 8:00 AM | 2:30 AM |
| 9:00 AM | 3:30 AM |
| 10:00 AM | 4:30 AM |
| 11:00 AM | 5:30 AM |
| 12:00 PM | 6:30 AM |
| 1:00 PM | 7:30 AM |
| 2:00 PM | 8:30 AM |
| 3:00 PM | 9:30 AM |
| 4:00 PM | 10:30 AM |
| 5:00 PM | 11:30 AM |
| 6:00 PM | 12:30 PM |
| 7:00 PM | 1:30 PM |
| 8:00 PM | 2:30 PM |
| 9:00 PM | 3:30 PM |
| 10:00 PM | 4:30 PM |
| 11:00 PM | 5:30 PM |
About these two clocks
IST — India Standard Time. Used in all of India — Mumbai, Delhi, Bengaluru. India does not use daylight saving time, so IST is UTC+5:30 all year.
GMT — Greenwich Mean Time. Used in UTC+0; the UK uses it in winter only. GMT itself never shifts. The UK leaves GMT for BST (UTC+1) from late March to late October, so “London time” and GMT differ in summer.
All figures on this page come from the IANA time zone database (the same data your phone and laptop use), evaluated for the date in question. Abbreviations are ambiguous — “IST” also means Irish or Israel Standard Time, and “CST” is China Standard Time in Asia — so this page uses Asia/Kolkata and Etc/GMT explicitly.
Questions people ask
How many hours ahead or behind is GMT compared with IST?
GMT is 5 h 30 min behind of IST all year, because the offset between the two clocks does not change.
What is 9 am IST in GMT?
On a January date, 9:00 am IST is 3:30 AM GMT. Use the converter above for any other date.
Which cities use IST?
India Standard Time (IST) is used in all of India — Mumbai, Delhi, Bengaluru. India does not use daylight saving time, so IST is UTC+5:30 all year.
Which cities use GMT?
Greenwich Mean Time (GMT) is used in UTC+0; the UK uses it in winter only. GMT itself never shifts. The UK leaves GMT for BST (UTC+1) from late March to late October, so “London time” and GMT differ in summer.
When is a good time for a IST–GMT call?
Look for the hours where both columns in the table fall between about 8 am and 6 pm. If none exist, the meeting planner on our home page shows the least-bad options and lets you share a link that converts for every attendee.
Related conversions
IST to ESTIST to UTCIST to CSTIST to PSTEST to GMTIST to CETPST to GMTUTC to GMTIST to AESTIST to JST