| Data type | Format | Function for loading data | Function for saving data |
| Surfaces (grids) | surfit native | surf_load | surf_save |
| Surfer ASCII-grd | surf_load_grd | surf_save_grd | |
| Surfer binary formats (v6, v7) | surf_load_grd | surf_save_grd | |
| Three columns XYZ files | surf_load_xyz | surf_save_xyz | |
| General Mapping Tools format | surf_load_gmt | surf_save_gmt | |
| Grass GIS ASCII format | surf_load_grass | surf_save_grass | |
| ArcGis ASCII grids | surf_load_arcgis | surf_save_arcgis | |
| JPG files | surf_load_jpg | surf_save_jpg | |
| BMP files | surf_load_bmp | ||
| Scattered points | surfit native | pnts_load | pnts_save |
| columned text files | pnts_read | pnts_write | |
| ESRI shape files (shp) | pnts_load_shp | ||
| 2D curves | surfit native | curv_load | curv_save |
| columned text files | curv_read | curv_write | |
| Surfer BLN files | curv_load_bln | curv_save_bln | |
| ESRI shape files (shp) | curv_load_shp | ||
| 3D curves (contours) | surfit native | cntr_load | cntr_save |
| columned text files | cntr_read | cntr_write | |
| Surfer BLN files | cntr_load_bln | cntr_save_bln | |
| ESRI shape files (shp) | cntr_load_shp | ||
| Areas (polygons) | surfit native | area_load | area_save |
| columned text files | area_read | area_write | |
| Surfer BLN files | area_load_bln | area_save_bln | |
| ESRI shape files (shp) | area_load_shp | ||
| DEMs | surfit native | dem_load | dem_save |
| Surfer ASCII-grd | dem_load_grd | dem_save_grd | |
| DTM | dem_load_dtm | dem_save_dtm | |
| HGT files (Shuttle Radar Topographic Mission files) | dem_load_hgt | ||
| zipped HGT files | dem_load_hgt_zip | ||
| GTOPO30/GLOBE files | dem_load_globe | ||
| Three columns XYZ files |
surfit: gridding and contouring software.