What Is My Location

NZTM Coordinate Converter

Tap once and you get your position as NZTM2000 easting and northing — the exact numbers printed on LINZ Topo50 map margins and used by DOC and Search and Rescue — plus the six-figure grid reference form for reading over the radio. Paste any NZTM pair and it converts back to a point on the map. One zone covers the whole country, the mathematics runs on your device, and the page keeps working offline in the backcountry.

How Topo50 sheet codes like BP34 work

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One zone for the whole country

UTM slices New Zealand awkwardly: the 174°E zone boundary runs almost through Auckland, splitting the country between zones 59 and 60 so positions either side of a line in the Waitākere Ranges live in different grids. NZTM2000 fixes that with a single national Transverse Mercator: central meridian 173°E, scale factor 0.9996, false origin 1,600,000 m east / 10,000,000 m north. The result is one seamless grid from Cape Reinga to Bluff — eastings run roughly 1.1–2.1 million, northings 4.7–6.2 million, which makes an NZTM pair instantly recognizable: a 7-digit number starting with 1 or 2, then a 7-digit number starting with 4, 5 or 6.

Topo50, DOC and Search and Rescue

NZTM is the grid on every LINZ Topo50 sheet, the coordinates DOC uses for huts and track markers, and what New Zealand Land Search and Rescue works from. For radio or phone, the six-figure form works exactly like everywhere else: chop the big digits, keep hundreds of metres — E 1,749,112 / N 5,428,741 reads as GR 491 287, naming a 100 m square. Quote your map sheet name alongside a six-figure reference (the full 7-digit pair needs no sheet — it's unique nationwide). This tool gives full NZTM numbers and the six-figure form; it doesn't compute Topo50 sheet codes like BP34 — read those off the map corner.

NZGD2000 and your GPS — nothing to correct

NZTM sits on the NZGD2000 datum, which agrees with the WGS84 your phone speaks to well under a metre — LINZ maintains the alignment with a deformation model that absorbs the ~5 cm/year plate drift. In practical terms: the NZTM values here are as good as your GPS fix, with no datum correction to apply. What actually limits you is the fix itself — sky view, canyon walls, beech canopy — which you can measure on the GPS accuracy page. If you're heading somewhere remote, load this page first: it computes on-device and keeps working with zero bars.

Edges of the grid

NZTM2000 covers the North, South and Stewart Islands and near-shore waters — the whole Topo50 map series. The Chatham Islands are the honest exception: they sit far enough east that LINZ gives them their own projection, CITM2000, so a Chathams position gets a clear message here instead of misleading numbers. Beyond New Zealand, UTM/MGRS is the worldwide equivalent, and Australia's MGA grid is the nearest national cousin. Quoting a position to emergency services? The emergency location guide covers exactly what to read out.

Frequently asked questions

Is NZTM the same as UTM?
Same projection mathematics, different constants. NZTM2000 is a single Transverse Mercator zone covering all of New Zealand — central meridian 173°E, false origin 1,600,000 / 10,000,000 — where UTM would split the country between zones 59 and 60 right through Auckland. The numbers are therefore completely different from UTM's; don't mix the two.
How do I read a six-figure grid reference from NZTM?
Chop to hundreds of metres: E 1,749,112 / N 5,428,741 becomes GR 491 287 — digits 2–4 of each value's last six. That names a 100 m square, repeating every 100 km, so quote your Topo50 sheet alongside it. The full 7-digit pair is unique nationwide and needs no sheet name.
Do I need to convert between NZGD2000 and WGS84?
No. NZGD2000 tracks WGS84 to well under a metre — LINZ's deformation model absorbs the plate motion — so GPS coordinates feed straight into NZTM with no datum step. Your GPS fix's own accuracy is the limiting factor, not the datum.
Why don't my old map's numbers match?
Maps from the NZMS 260 era (before Topo50, 2009) used NZMG on the older NZGD1949 datum — a different projection with different numbers, offset by roughly 200 m at the datum level. There's no quick mental fix between NZMG and NZTM; use LINZ's conversion tools for old references. Everything Topo50-era is NZTM.
Does it cover the Chatham Islands?
No — and that's the grid's own design, not a gap in this tool. The Chathams sit far enough east that LINZ projects them separately as CITM2000. A Chathams position here gets a clear message to that effect rather than misleading NZTM numbers.
Related tools
UTM Coordinates for My Location See your UTM and MGRS coordinates in one tap, or convert between UTM and latitude/longitude in both directions. WGS84, meter-level accuracy, free, private. MGA Coordinates Converter Get your MGA coordinates on GDA2020 in one tap — zone, easting, northing plus a six-figure map reference — or convert any MGA position back to a map point. Coordinate Converter Convert coordinates between decimal degrees, DMS, DDM, UTM, MGRS, Plus Code and geohash. Paste any format, click the map, get all 8 instantly. How to Share Your Exact Location in an Emergency Get your exact GPS coordinates in one tap and share them by call, text, or maps link — plus what 911/112 sees automatically, and what to do with no signal. How to Quote a Topo50 Map Reference How New Zealand's Topo50 sheet codes like BP34 work, and how to quote a six-figure reference with the sheet — the format DOC and NZ rescue teams use.