Abstract Measurements of both horizontal and vertical surface displacements allow for rigorous estimation of the moment deficit and the fault locking along subduction zones, including continental megathrusts. Previous measurements in the Himalayas were restricted to horizontal velocities from Global Navigational Satellite Systems, so the locking and the width of transition from apparent locking to interseismic creep were not well constrained. We present new observations of surface deformation from interferometric synthetic aperture radar for approximately 800 km along Himalaya. The interseismic velocity field along arcāperpendicular transects suggests a 5ā8 mm/yr uplift in the higher Himalayas. We infer that the megathrust accommodates 20ā22 mm/yr convergence over a width of ā¼115 km from the frontal thrust followed by a ā¼40 km transition zone. Sufficient strain has accumulated over the past 5ā7 centuries in the central seismic gap that could be released by two Mw 8.8 earthquakes.