Zerdly

Point List Renumber Tool

Renumbers the mapped point-ID column of a survey CSV from a start number and step, with exact integer arithmetic, optional prefix and padding, collision checks and an old-to-new mapping file. Every other field is left exactly as read.

100% FreeRuns in your browserBasic
How to use this calculator

Point list and numbering

Only the mapped ID column changes. Coordinates, codes and notes are carried through exactly as read.

Paste, or open a local file — it is read in this browser and never uploaded. Limits: 10 MiB, 100,000 records, 200 fields per record and 100,000 characters per field. Nothing is ever truncated — a file over a limit is refused with the reason.

New numbers

Whole number; exact at any size.

Non-zero; negative counts down.

4 gives 0007. Blank = no padding.

Generated IDs that match any of these are collisions and block the download.

Paste or open a point list, check the ID column and press Renumber and preview.

One logical record can span lines
Illustrative
One logical record can span linesFour physical lines of a CSV file hold three logical records. The quoted note on record 2 contains a line break, so it continues onto line 3 inside the same cell. The comma inside the quotes on line 4 is text, not a delimiter. The ID 0007 and the decimal 123.4500 are kept exactly as typed.line1234ID,Easting,Northing,Note0007,123.4500,456.78,"two spacesnext line"0008,100.0,200.10,"kerb, east side"← same record4 physical lines · 3 logical records · 4 fields each
Lines 2 and 3 are one record: the quoted line break stays inside the Note cell. A comma inside quotation marks is not a delimiter. 0007 keeps its leading zeros and 123.4500 keeps its decimal places.

How to use this calculator

  1. Paste the point list or open the file, check the delimiter and header toggle, and confirm which column holds the point ID in the mapping preview.
  2. Enter the start number and a non-zero step (negative counts down), plus an optional prefix and zero-padding width. Optionally paste IDs already used elsewhere so collisions are caught.
  3. Press Renumber and preview, read the old-to-new mapping and the output preview, then download the renumbered file and the mapping file.

How it works

For the i-th numbered data record (i = 0, 1, 2 …) the new ID is prefix + pad(start + i × step). The arithmetic uses exact integers (BigInt), so very large point numbers are not rounded.

Only the mapped ID column is rewritten. Every other field is carried through as the exact text that was read — coordinates such as 001.230, codes and quoted notes do not change. The header is never renumbered, and input order is kept.

Blank records stay in place unnumbered unless you choose to remove them; removals are listed. A step of 0, a sequence that drops below zero, or a new ID that is already in your existing-ID list blocks the download.

Old IDs that appear on more than one record are flagged, because references to them cannot be updated from the mapping alone.

Worked example

Three points renumbered from 1000. With a header Point,Easting,Northing,RL,Code and IDs 0001, 0002 and 0003, start 1000 and step 1 give 1000, 1001 and 1002. The RL 001.230 on the third point is still 001.230 and the quoted code "IP, east" keeps its comma. With start 30, step −10, prefix CP and padding 3 the IDs become CP030, CP020 and CP010.

Frequently asked questions

Can I keep leading zeroes?

Yes. Set the padding width — 4 turns 7 into 0007. Fields in other columns that already have leading zeros keep them, because nothing outside the ID column is changed.

Will coordinates change?

No. Coordinates, heights and codes are copied as the exact text read from the file; there is no rounding or number formatting.

How do I update references to old IDs?

Download the old-to-new mapping CSV and use it to update linework, stringlines and any other file that names the old IDs. If an old ID appeared twice, the tool warns you because those references are ambiguous.

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.

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Cite this tool

Zerdly. (2026). Point List Renumber Tool. Retrieved from https://www.zerdly.com/tools/point-list-renumber-tool/

Tip: Enter any known values to calculate the remaining results.

Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.