Point List Duplicate and Gap Checker
A free, browser-based file tool. Runs entirely in your browser — no sign up, nothing stored.
Paste your point list
First column is the point number, then easting and northing. A header row is detected and skipped. Runs in your browser — nothing is uploaded.
Report
Paste a point list to check it.
How to use this calculator
- Paste your point list with the point number first, then easting and northing.
- A header row is detected and skipped automatically.
- Read the report: duplicate numbers, missing ranges, coincident coordinates and invalid rows.
How it works
The checker reads each row, then cross-checks the set: point numbers that repeat, integer point numbers with gaps in the sequence, and different points sharing the same coordinate within a small tolerance.
Rows with a missing point number or non-numeric easting/northing are listed separately so you can fix the source data before importing.
Worked example
A list with point 2 twice and 3–4 missing. For points 1, 2, 2, 5 the tool flags point 2 as duplicated, reports the missing range 3–4, and notes any two points sharing the same coordinate.
Frequently asked questions
What counts as a coincident coordinate?
Two different point numbers whose easting and northing match within about a millimetre. That usually means a point was recorded twice under different numbers, or a typo.
Why does it skip my first row?
If the first row has non-numeric coordinates it's treated as a header and ignored. Remove the header if your first line is real data.
Is this official course material?
No. It is free study support mapped to surveying course levels — not official North Metropolitan TAFE content or advice. Always follow your lecturer and the official assessment brief, and check your own working.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.