You will get an arrival Visa for Nepal at Kathmandu International Airport upon arrival. If you fill up this form Department of Immigration Nepal and bring it with you. It will be much faster and avoid the long queue.
15 days: US $ 30 or equivalent foreign currency for Tourist visas with Multiple Entries.
30 days: US $ 50 or equivalent foreign currency for Tourist visas with Multiple Entries.
100 days: US $ 125 or equivalent foreign currency for Tourist visas with Multiple Entries.
Regardless of the provision, tourists with a passport from South Asian Association for Regional Cooperation (SAARC) nations doesn’t require to pay a visa fee for 30 days. However, Indian nationals do not require a visa to enter Nepal.