Chainage, Offset and Level Profile Along a Centreline
Last updated 26 September 2026
Give every point its chainage along a road, pipe or kerb line and its offset left or right, and save a level profile with grades.
What you get
- Chainage and offset: for every point, how far along a centreline it is and how far to the left or right of it. The usual way to describe a road, pipeline or channel survey.
- Level profile: the levels along one line, with the chainage and the grade between each pair of points.
Chainage and offset
- Give the centreline points their own code — CL, a kerb, a pipe — and keep them in order along the line in the sheet.
- Load the sheet in the web app or the Windows app and open Lines and areas.
- Under Chainage and offset against a centreline, choose the centreline code. Every other point is dropped square onto the nearest leg of the line.
- Press Save chainage sheet.
The sheet lists every point in chainage order with its code, chainage in the usual 0+125.40 form and in metres, offset in metres, and which side it lies — right positive, left negative, looking along the line from its start. Points before the start or past the end of the line are noted, so they aren't mistaken for points beside it.
Level profile
- Set up the line under Lines and areas — see boundaries and land area for joining points by code.
- Under Level profile, pick the line. The profile is drawn with its levels and grades.
- Press Save profile sheet for a CSV with station, chainage, level and grade in percent between each point and the one before.
Good to know
- Chainage is worked on the grid when the sheet has eastings and northings, and on the ground from latitude and longitude when it doesn't.
- The centreline needs at least two points with the chosen code. More points follow the bends more closely.
- A point with no level is left blank in the profile, and the grade on either side of it is skipped.
Try it with your own sheet