Dress code in Iran for tourist:  as travelers to Iran you may hear about Iran Dress Code and Women's hijab and makes lots of questions of what should you wear? As a matter of fact, since the revolution of 1979 all women in Iran, including foreigners, have been required by law to wear loose-fitting clothes to disguise their figures. In different cities of Iran, Iranian ladies' outfit is different but our tourist ladies do not need to worry about this diversity. 
This information below aims to give practical advice, dispel preconceptions and reassure.

As women traveler to Iran:
What Should I Wear? Ladies Dress Code in Iran:
Wearing head scarf and long trousers are mandatory in Iran. You are supposed to hide your body shape, according to Iran dress codes for tourists.
Head scarf:
There is no limitation for choosing scarf. You are not obligated to put on a tight scarf, however rules are not observed very strict, especially for tourists and foreigners. The scarf can have any color and pattern that you might wish. The super light colored scarf and light material are recommended for summer trip to Iran and for winter it is better to wear the warm cloths to protect your head, ears and neck from cold.
Your body must be covered by loose clothing, the size is different. Most of Iranian ladies prefer to wear the long tunic to kneel (a button-up tunic with long sleeves named man-teus). You can wear baggy shirts on warm days and warm clothes during winter. 
Jeans are absolutely fine which is the most common among Iranians (men and women)
Shoes: Feet could be uncovered. As foot wear, open-toed sandals are fine but wearing flip-flops outside in Iran is unusual.
In general our tourist ladies can stay as stylish as they wish in Iran as long as their hair is covered.
It is better to find Iran Dress Code out before traveling to Iran 

Men Dress Code in Iran:
Long pants: Men are similarly required to wear long pants.
T-shirts: Men are supposed to wear long sleeved shirts but t-shirts would be fine.
Shoes: you can wear any type of shoes but as was mentioned before, wearing flip-flops are not usual outside.
The dress code in Holy places:
For visiting shrines and some mosques wearing Chador is mandatory. You can rent it at that place or buy in cheap price in stores. 

Where can buy Iranian cloth?
When you arrive at the airport, you need to be dressed according to Iran dress codes. You could bring something suitable you already have and buy some cloths at the local markets where you can find many beautiful cloths in colors and various significant designs.

 Iran female Dress Code Business visitors:

Iran female dress code Business Visitors: In case you are a business traveler, you should notice that you have to wear dark outfits with dark colored scarf in offices with covered shoes, would be great choices to wear in a business meeting. 

Iran Dress Code for Male Tourists as Business Visitors:
At business or formal occasions, a suit is generally acceptable for men. The difference is almost the absence of tie especially in government-affiliated companies or government organizations.

Iranians are aware of various dress styles so you could follow your own style and wear a tie as foreign leaders and diplomas do. Some Iranian private businesspersons also wear a tie.