Kalpa is linked with Reckong Peo by several buses daily, first one at 6 am. Otherwise it's a 45 minutes walk downhill or a 250 rs taxi ride if you arrange a taxi from Reckong Peo to pick you up.
From ShimlaKalpa is approximately 250 km from Shimla, via National Highway 22 also known as the Hindustan Tibet Road till Poari. From Poari, take the deviation to Reckong Peo and then to Kalpa.
By BusHimachal Road Transport Corporation HRTC (http://hrtc.gov.in) runs three buses daily on this route from end to end - one ordinary bus that leaves Shimla from Riwari bus stand at 6:45 AM, one that leaves at 23:15 hours and one deluxe bus coming from Chandigarh going to Reckong Peo at 11:00 AM. Buses will take 10-12 hours to ply this distance. You can check the exact timings at the HRTC website (http://hrtc.gov.in/route.asp) and searching separately for Kalpa and Reckong Peo.
By TaxiTaxis can be hired for rates starting from 1500 INR per day from the mall or through the hotels. Taxis would take 10 hours to ply this route. A good option would be to break the journey at Rampur or Sarahan and then continue the next day