GMT to IST Converter

Here GMT means Greenwich Mean Time, fixed at UTC+0 (the UK itself moves to BST, UTC+1, in summer); IST means India Standard Time, UTC+5:30 all year. So IST is always 5 h 30 min ahead of GMT. Two 9-to-5 working days overlap by 2 h 30 min all year.

GMT to IST is searched by people linking Britain and India: families, students in UK universities, and companies with offices in London and Bengaluru. Fixed GMT is 5 h 30 min behind India all year, which is the number this page uses. Britain’s own clocks are a different matter, because the UK is on GMT only in winter.

From the last Sunday in March to the last Sunday in October London runs on BST, an hour ahead of GMT, so London is then 4 h 30 min behind India rather than 5 h 30 min. A meeting fixed at 10:00 am London time therefore lands at 3:30 pm in India in winter but 2:30 pm in summer. If someone in the UK writes “GMT” in June, they almost always mean the clock on their wall, which is BST; ask, or convert from London time instead. The London and India city pages show both clocks live.

Rule of thumb: Add 5½ hours to GMT for Indian time; from a London clock in summer (BST), add 4½.