Three numbers. The ones that decide the meeting.
When the world meets at work.
Read the day in both zones.
Crossing the border. Money, language, plugs.
Money changes hands at the border: Tehran uses the IRR (﷼) and St. Louis uses the USD ($). Language shifts too — Persian (Farsi) in Tehran, English in St. Louis. Cars drive on the right in both, so rentals feel familiar.
- Country
- Iran
- Capital
- Tehran
- Currency
- Iranian rial (IRR · ﷼)
- Language
- Persian (Farsi)
- Calling code
- +98
- Drives on
- Right
- Country
- United States
- Capital
- Washington, D.C.
- Currency
- United States dollar (USD · $)
- Language
- English
- Calling code
- +1
- Drives on
- Right
Quick answers. Before you book the call.
What's the time difference between Tehran and St. Louis?
Tehran is 8.5 hours behind St. Louis. Tehran runs on GMT+3:30 and St. Louis on GMT-5. The gap can shift by an hour when either side enters or leaves daylight saving — the live clocks above always reflect the current offset.
When's the best time to schedule a meeting?
Standard 09:00–17:00 workdays don't intersect. Most teams compromise with one side meeting early (before 09:00) or late (after 17:00).
Does daylight saving time change the difference?
Yes, if either city observes DST. When one side shifts and the other doesn't, the gap changes by one hour. The DST badges under each clock show whether each zone is currently shifted and when the next transition lands.
How far is Tehran from St. Louis?
About 10,857 km as the crow flies (great-circle distance). A non-stop commercial flight cruises that in roughly 13h 16m, not counting airport time, winds, or routing around restricted airspace.
Can I send this meeting time as a calendar invite?
Yes. Pick a time on the slider above, open the meeting card, customize the title and duration, then download the .ics file. It imports cleanly into Google Calendar, Outlook, and Apple Calendar with the correct timezone attached.
What currency do Tehran and St. Louis use?
Tehran uses the Iranian rial (IRR, ﷼); St. Louis uses the United States dollar (USD, $). Check the live rate before transferring money or paying with a card abroad — most banks add a 1–3 % FX margin on top of the mid-market rate.
How do I call Tehran from St. Louis?
Dial the international prefix used by your carrier (often 011), then +98, then the local number — drop any leading zero of the city or mobile code. For free calls, WhatsApp, Signal, and FaceTime work over Wi-Fi regardless of country code.
What language is spoken in Tehran and St. Louis?
Tehran primarily speaks Persian (Farsi); St. Louis speaks English. English is widely used in business contexts in major cities of both, but written contracts may need translation.
Do Tehran and St. Louis drive on the same side of the road?
Yes — both drive on the right. Rental cars feel identical between the two.