Nepal Visa Information: Travelers need passports with less than 6 months of validity for visas.

Nepal Tourist visa:

The foreign tourists visiting Nepal can get a visa on arrival.
The tourist visa is for a maximum of 150 days a year  (Visa years mean January to December).

Moreover, if any foreigner who has entered Nepal towards the end of a visa year desires to spend even the period during which he may stay in Nepal with the tourist visa of the other visa year, he may use such facility.
Provided, however, that the computation of the fees for such period shall be made on the basis of the total period of his stay.

Therefore, an application for the tourist visa has to be submitted in the format referred to in Appendix 1.
Transit Visa:

An application for the transit visa has to be submitted in the format referred to in Appendix 3.

Types and costs:

The fee for a Single Entry Tourist Visa to Nepal for 60 days is US$ $60 or the equivalent foreign currency
Additional $50 grants for Multiple Entry Visas
A tourist visa is possible to extend up to 150 days. The Visa extension fee for 30 days is US$ 30
Validity:

The Visas are valid for up to six months from the date of issue. Visas are valid for 60 days on the first visit to Nepal in a visa year (1 January-31 December), but only valid for 30 days when a national is visiting Nepal for the second or more time in a visa year. Visas is possible to extend in Nepal at the Department of Immigration, Kathmandu (tel: 494 273 or 337), or the Immigration Office, Pokhara. The maximum stay in Nepal is 150 days in any calendar year. For full conditions on visa extension (including charges and conditions), contact the consulate (or consular section at the embassy); see Important Addresses.

Application to:

Consulate (or consular section at embassy). Visas are able to get on arrival from the immigration authorities at all entry points (with fees payable in US Dollars) provided travelers are in possession of valid travel documents, two passport photos, and the relevant fee.

Additionally, working days required:

Minimum 24 hours if applying in person; two weeks if applying by post.

Extension of Stay: Nepal Visa Information

A tourist visa is possible to extend from the Department of Immigration and Pokhara Immigration Office for a total of 120 days. An additional 30 days visa is possible from the department. Over the course of a visa year, a tourist cannot stay in Nepal for more than cumulative 150 days.