Grid ↔ Ground Converter — Combined Scale Factor
Point and line scale factor from MGA2020 grid coordinates, height factor from an ellipsoidal height or an AHD height plus an N value, and the combined scale factor — then convert a distance grid → ground or ground → grid with every step of the working shown.
Free advisory field tool — every result is computed in your browser from the inputs you provide and is advisory and unverified, not for survey deliverables. Where a published guideline applies, results only ever read “within guideline” or “exceeds guideline — review”. The full working is shown for every calculation so each step can be re-checked. Registered surveyor confirmation required before reliance.
Leave blank to compute the factors only.
Enter the point (and a height) to compute the factors — the result and its full working appear here.
Height note: the height factor needs the ellipsoidal height. If you work in AHD, supply the N value (geoid–ellipsoid separation) from your AUSGeoid model output and the tool shows the h = H + N step in the working — automatic AUSGeoid lookup is coming in a later update (B7.1). Line scale here is the short-line convention (mean of the endpoint point scale factors).
Advisory output — confirm independently before reliance.
Safety & scope
SurveyMarkup does not certify survey accuracy, cadastral compliance, legal boundaries, or coordinate correctness. It helps prepare and review working information, but original data and final outputs must be checked by a qualified user before use.
Assistance only - professional review remains required.