Algeria Lambert: convert GPS to North and South Lambert
Northern Algeria uses two Lambert conformal conic zones on the Nord Sahara 1959 datum (Clarke 1880 ellipsoid): North Algeria (EPSG:30791, parallel 36° N) and South Algeria (EPSG:30792, parallel 33°18′ N), both on the 2°42′ E meridian. The Sahara is mostly worked in UTM, zones 29 to 32. The converter goes from GPS (WGS 84) to these systems and back, with the most accurate datum transformation in the EPSG registry.
- EPSG:30791
- EPSG:30792
- UTM 29–32 N
- Computed in your browser: no coordinate is sent or stored, and no account is needed.
- Definitions checked against the EPSG registry with PROJ: less than a millimetre apart on all 32 systems.
Coordinate converter
Edit either side, the other follows.
For this point:
Batch conversion
One point per line: a name, then X and Y (or latitude and longitude), and Z if you have it. Separators: semicolon, tab, comma or space.
Which zone for which region?
Carte suggests Lambert North north of 34°39′ N (38.5 grads, half way between the two parallels) — Algiers, Oran, Constantine, Annaba, Tlemcen, Biskra — and Lambert South down to 31°57′ N — Laghouat, El Oued, Ghardaia. Further south — Ouargla, Bechar, Adrar, Tamanrasset — it suggests UTM, whose zone follows the longitude: 29 west of 6° W (Tindouf), 30 up to Greenwich (Oran, Bechar), 31 up to 6° E (Algiers, Ghardaia), 32 beyond (Constantine, Annaba). Always check the system the plan or the specification requires.
Projection parameters
The EPSG registry values — the ones the converter, Carte and MawCAD use.
| System · Projection | EPSG | Latitude of origin | Central meridian | Scale factor k₀ | False origin X₀ / Y₀ | Suggested latitudes |
|---|---|---|---|---|---|---|
| AN Algeria Lambert NorthNord Sahara 1959 / Nord AlgerieLambert conformal conic, 1 parallel | EPSG:30791 | 36° (40 gr) | 2.7° (3 gr) | 0.999625544 | 500,135 / 300,090 | north of 34°39′ N |
| AS Algeria Lambert SouthNord Sahara 1959 / Sud AlgerieLambert conformal conic, 1 parallel | EPSG:30792 | 33.3° (37 gr) | 2.7° (3 gr) | 0.999625769 | 500,135 / 300,090 | 31°57′ – 34°39′ N |
Datum and the shift to WGS 84
The Nord Sahara 1959–WGS 84 step uses transformation EPSG:10296 (Nord Sahara 1959 to WGS 84 (11)), a seven-parameter set stated to about 1 m across the country. Without any datum shift, points move by 70 to 80 m; the older three-parameter shifts, still common in some software, leave a few metres: check your software's transformation before mixing data.
| Datum | Ellipsoid | a / 1/f | Transformation to WGS 84 | Stated accuracy |
|---|---|---|---|---|
| Nord Sahara 1959 | Clarke 1880 (RGS) | 6,378,249.145 m / 293.465 | Nord Sahara 1959 to WGS 84 (11) (EPSG:10296) ΔX ΔY ΔZ = −267.407 · −47.068 · 446.357 m Rx Ry Rz = −0.179423 · 5.577661 · −1.27762″ · ds = 1.204866 ppm | ± 1 m |
| WGS 84 | WGS 84 | 6,378,137.000 m / 298.257223563 | none | — |
Coordinates of the main cities
Approximate city centre. X and Y in metres, computed with the same definitions as the converter.
| City | Lat., long. (WGS 84) | National Lambert | UTM (WGS 84) | Map |
|---|---|---|---|---|
| Algiers | 36.75383.0588 | AN X 532,233.58Y 383,751.88 | 31NE 505,248.61N 4,067,562.78 | Map |
| Oran | 35.6971−0.6308 | AN X 198,907.22Y 271,625.63 | 30NE 714,363.58N 3,952,940.20 | Map |
| Constantine | 36.36506.6147 | AN X 851,316.01Y 347,613.90 | 32NE 285,995.08N 4,027,075.69 | Map |
| Annaba | 36.90007.7667 | AN X 951,473.85Y 411,644.81 | 32NE 390,119.89N 4,084,489.25 | Map |
| Blida | 36.47002.8277 | AN X 511,644.09Y 352,216.75 | 31NE 484,563.67N 4,036,094.17 | Map |
| Setif | 36.19115.4137 | AN X 744,168.14Y 324,668.71 | 31NE 717,034.59N 4,007,844.89 | Map |
| Bejaia | 36.75255.0556 | AN X 710,476.26Y 386,090.01 | 31NE 683,501.58N 4,069,387.10 | Map |
| Tizi Ouzou | 36.71694.0497 | AN X 620,746.75Y 380,434.03 | 31NE 593,744.81N 4,063,981.36 | Map |
| Chlef | 36.16531.3345 | AN X 377,390.59Y 319,269.90 | 31NE 350,199.87N 4,003,567.92 | Map |
| Tlemcen | 34.8783−1.3150 | AN X 133,309.06Y 183,217.57 | 30NE 653,994.09N 3,860,842.21 | Map |
| Batna | 35.55506.1741 | AN X 815,017.51Y 256,329.33 | 32NE 243,851.29N 3,938,268.14 | Map |
| Biskra | 34.85045.7280 | AN X 777,034.40Y 176,868.22 | 31NE 749,419.69N 3,859,847.76 | Map |
| Djelfa | 34.67283.2630 | AN X 551,796.73Y 153,017.02 | 31NE 524,094.36N 3,836,790.27 | Map |
| Laghouat | 33.80002.8650 | AS X 515,477.73Y 355,511.32 | 31NE 487,503.90N 3,739,988.92 | Map |
| El Oued | 33.36836.8674 | AS X 887,788.29Y 315,374.87 | 32NE 301,594.97N 3,694,149.39 | Map |
| Ghardaia | 32.49093.6735 | AS X 591,673.54Y 210,787.74 | 31NE 563,275.02N 3,595,050.14 | Map |
| Ouargla | 31.94935.3250 | use UTM | 31NE 719,756.17N 3,537,176.22 | Map |
| Bechar | 31.6167−2.2167 | use UTM | 30NE 574,294.06N 3,498,217.30 | Map |
| Adrar | 27.8742−0.2939 | use UTM | 30NE 766,435.08N 3,086,210.07 | Map |
| Tamanrasset | 22.78505.5228 | use UTM | 31NE 759,007.04N 2,521,928.94 | Map |
UTM zones
UTM cuts the globe into 6° zones of longitude, all on WGS 84: scale factor 0.9996 on the central meridian, X₀ = 500,000 m, Y₀ = 0 north of the equator. Zones 28 to 32 N cover Morocco, Algeria, Tunisia and France; a point's zone follows from its longitude.
| Zone | EPSG | Central meridian | Longitudes | Countries |
|---|---|---|---|---|
| 29N WGS 84 / UTM zone 29N | EPSG:32629 | −9° | −12° → −6° | Morocco · Algeria |
| 30N WGS 84 / UTM zone 30N | EPSG:32630 | −3° | −6° → 0° | Morocco · Algeria · France |
| 31N WGS 84 / UTM zone 31N | EPSG:32631 | 3° | 0° → 6° | Algeria · France |
| 32N WGS 84 / UTM zone 32N | EPSG:32632 | 9° | 6° → 12° | Algeria · Tunisia · France |
Frequently asked questions
What is the EPSG code of Algeria Lambert North?
EPSG:30791 (Nord Sahara 1959 / Nord Algerie); Algeria Lambert South is EPSG:30792. In UTM: EPSG:30729 to 30732 on Nord Sahara 1959, EPSG:32629 to 32632 on WGS 84.
Algeria Lambert North or South: which one?
The one of the site's latitude: Lambert North north of about 34°39′ N, Lambert South between 31°57′ and 34°39′ N. The converter suggests it as soon as you enter a GPS position. If the existing plan is in the other zone, keep the plan's.
Should I work in Lambert or in UTM in Algeria?
Follow the specification or the existing plan. Older plans of the North are often in Lambert North or South (Nord Sahara 1959); UTM, on WGS 84 or on Nord Sahara 1959, is common for large projects and in the Sahara. The converter goes from one to the other.
Do the coordinates have legal value?
No: they are for locating, checking and preparing. A land deed or a boundary marking relies on a survey tied to the national geodetic network by a licensed land surveyor (géomètre-expert foncier).
Can I convert a list of points at once?
Yes: open “Batch conversion”, paste your points — one per line, with a name, the two coordinates and Z if you have it — then download the result as CSV or copy it into a spreadsheet. Nothing is sent: everything is computed in the browser.
Survey in this zone
Carte opens the satellite imagery straight in the chosen zone: points, lines and areas with live X/Y, export to DXF, Shapefile (with .prj) or KML. With a free account, the survey moves on to MawCAD for CAD drafting.