Lambert-93: convert GPS coordinates to Lambert
Lambert-93 (EPSG:2154) is the official projection of metropolitan France: a secant conformal conic on the RGF93 system (GRS 80 ellipsoid), with the 44° and 49° N parallels, the 3° E meridian and the origin X = 700,000 m, Y = 6,600,000 m. Nine conformal conic projections, CC42 to CC50, complement it where less linear distortion is needed. The converter goes from GPS to these systems — and to the old NTF Lambert I to IV — in both directions.
- EPSG:2154
- EPSG:3942
- EPSG:3943
- EPSG:3944
- UTM 30–32 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.
Lambert-93, CC or Lambert II extended?
Lambert-93 covers all of metropolitan France in one piece, at the cost of a linear distortion running from −1 m/km in the centre (46°30′ N) to +3 m/km south of Corsica. The CC42 to CC50 zones, each centred on a whole parallel, bring it under 9 cm/km within one degree of their parallel: take the one whose number is the nearest latitude — CC49 for Paris, CC46 for Lyon, CC43 for Marseille. Tip: the millions digit of Y, plus 41, gives the zone (a Y of 8,184,000 m is in CC49). Lambert II extended (NTF, Paris meridian) is still common on plans drawn before 2000.
Projection parameters
The EPSG registry values — the ones the converter, Carte and MawCAD use.
| System · Projection | EPSG | Latitude of origin | Central meridian | Standard parallels | Scale factor k₀ | False origin X₀ / Y₀ |
|---|---|---|---|---|---|---|
| L93 Lambert-93RGF93 v1 / Lambert-93Lambert conformal conic, 2 parallels | EPSG:2154 | 46.5° | 3° | 44° · 49° | — | 700,000 / 6,600,000 |
| FCC42 CC42RGF93 v1 / CC42Lambert conformal conic, 2 parallels | EPSG:3942 | 42° | 3° | 41.25° · 42.75° | — | 1,700,000 / 1,200,000 |
| FCC43 CC43RGF93 v1 / CC43Lambert conformal conic, 2 parallels | EPSG:3943 | 43° | 3° | 42.25° · 43.75° | — | 1,700,000 / 2,200,000 |
| FCC44 CC44RGF93 v1 / CC44Lambert conformal conic, 2 parallels | EPSG:3944 | 44° | 3° | 43.25° · 44.75° | — | 1,700,000 / 3,200,000 |
| FCC45 CC45RGF93 v1 / CC45Lambert conformal conic, 2 parallels | EPSG:3945 | 45° | 3° | 44.25° · 45.75° | — | 1,700,000 / 4,200,000 |
| FCC46 CC46RGF93 v1 / CC46Lambert conformal conic, 2 parallels | EPSG:3946 | 46° | 3° | 45.25° · 46.75° | — | 1,700,000 / 5,200,000 |
| FCC47 CC47RGF93 v1 / CC47Lambert conformal conic, 2 parallels | EPSG:3947 | 47° | 3° | 46.25° · 47.75° | — | 1,700,000 / 6,200,000 |
| FCC48 CC48RGF93 v1 / CC48Lambert conformal conic, 2 parallels | EPSG:3948 | 48° | 3° | 47.25° · 48.75° | — | 1,700,000 / 7,200,000 |
| FCC49 CC49RGF93 v1 / CC49Lambert conformal conic, 2 parallels | EPSG:3949 | 49° | 3° | 48.25° · 49.75° | — | 1,700,000 / 8,200,000 |
| FCC50 CC50RGF93 v1 / CC50Lambert conformal conic, 2 parallels | EPSG:3950 | 50° | 3° | 49.25° · 50.75° | — | 1,700,000 / 9,200,000 |
| F1 Lambert INTF (Paris) / Lambert Nord FranceLambert conformal conic, 1 parallel | EPSG:27561 | 49.5° (55 gr) | 0° Paris | — | 0.999877341 | 600,000 / 200,000 |
| F2 Lambert IINTF (Paris) / Lambert Centre FranceLambert conformal conic, 1 parallel | EPSG:27562 | 46.8° (52 gr) | 0° Paris | — | 0.99987742 | 600,000 / 200,000 |
| F3 Lambert IIINTF (Paris) / Lambert Sud FranceLambert conformal conic, 1 parallel | EPSG:27563 | 44.1° (49 gr) | 0° Paris | — | 0.999877499 | 600,000 / 200,000 |
| F4 Lambert IVNTF (Paris) / Lambert CorseLambert conformal conic, 1 parallel | EPSG:27564 | 42.165° (46.85 gr) | 0° Paris | — | 0.99994471 | 234.358 / 185,861.369 |
| F1C Lambert I cartoNTF (Paris) / Lambert zone ILambert conformal conic, 1 parallel | EPSG:27571 | 49.5° (55 gr) | 0° Paris | — | 0.999877341 | 600,000 / 1,200,000 |
| F2C Lambert II extendedNTF (Paris) / Lambert zone IILambert conformal conic, 1 parallel | EPSG:27572 | 46.8° (52 gr) | 0° Paris | — | 0.99987742 | 600,000 / 2,200,000 |
| F3C Lambert III cartoNTF (Paris) / Lambert zone IIILambert conformal conic, 1 parallel | EPSG:27573 | 44.1° (49 gr) | 0° Paris | — | 0.999877499 | 600,000 / 3,200,000 |
| F4C Lambert IV cartoNTF (Paris) / Lambert zone IVLambert conformal conic, 1 parallel | EPSG:27574 | 42.165° (46.85 gr) | 0° Paris | — | 0.99994471 | 234.358 / 4,185,861.369 |
Datum and the shift to WGS 84
RGF93 matches WGS 84 to better than a metre: transformation EPSG:1671 is a null one, and Lambert-93 X/Y follow directly from a GPS position. For the old NTF (Lambert I to IV, Lambert II extended), the converter applies the three-parameter shift EPSG:1193 (−168 m, −60 m, 320 m), accurate to about 2 m; IGN's finer conversion grid is not applied here.
| Datum | Ellipsoid | a / 1/f | Transformation to WGS 84 | Stated accuracy |
|---|---|---|---|---|
| RGF93 v1 | GRS 1980 | 6,378,137.000 m / 298.257222101 | RGF93 v1 to WGS 84 (1) (EPSG:1671) | ± 1 m |
| NTF (Paris) | Clarke 1880 (IGN) | 6,378,249.200 m / 293.466021294 | NTF to WGS 84 (1) (EPSG:1193) ΔX ΔY ΔZ = −168 · −60 · 320 m | ± 2 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 | CC conformal conic | Lambert II extended | UTM (WGS 84) | Map |
|---|---|---|---|---|---|---|
| Paris | 48.85662.3522 | L93 X 652,469.02Y 6,862,035.26 | CC49X 1,652,467.87Y 8,184,256.87 | X 601,152.30Y 2,428,695.90 | 31NE 452,482.53N 5,411,717.18 | Map |
| Lille | 50.62923.0573 | L93 X 704,061.15Y 7,059,136.59 | CC50X 1,704,054.20Y 9,269,986.10 | X 651,112.23Y 2,626,335.52 | 31NE 504,052.68N 5,608,593.41 | Map |
| Reims | 49.25834.0317 | L93 X 775,113.84Y 6,907,006.50 | CC49X 1,775,092.22Y 8,229,234.03 | X 723,489.40Y 2,474,729.77 | 31NE 575,069.56N 5,456,682.52 | Map |
| Strasbourg | 48.57347.7521 | L93 X 1,050,362.70Y 6,840,899.65 | CC49X 2,050,430.42Y 8,163,534.88 | X 999,472.19Y 2,410,952.53 | 32NE 407,949.38N 5,380,786.13 | Map |
| Brest | 48.3904−4.4861 | L93 X 146,632.98Y 6,836,262.33 | CC48X 1,146,480.42Y 7,270,301.30 | X 95,210.27Y 2,398,759.85 | 30NE 389,984.03N 5,360,759.93 | Map |
| Rennes | 48.1173−1.6778 | L93 X 352,107.38Y 6,789,966.54 | CC48X 1,351,952.27Y 7,223,603.68 | X 301,195.11Y 2,354,093.79 | 30NE 598,405.45N 5,330,183.19 | Map |
| Nantes | 47.2184−1.5536 | L93 X 355,577.80Y 6,689,723.10 | CC47X 1,355,306.36Y 6,234,298.86 | X 305,486.75Y 2,253,807.09 | 30NE 609,513.62N 5,230,449.22 | Map |
| Dijon | 47.32205.0415 | L93 X 854,184.55Y 6,693,290.46 | CC47X 1,854,304.79Y 6,237,805.82 | X 804,434.64Y 2,261,547.90 | 31NE 654,268.69N 5,242,968.76 | Map |
| Lyon | 45.76404.8357 | L93 X 842,666.66Y 6,519,924.37 | CC46X 1,842,779.11Y 5,175,416.43 | X 794,390.28Y 2,087,943.39 | 31NE 642,744.98N 5,069,465.46 | Map |
| Grenoble | 45.18855.7245 | L93 X 913,924.10Y 6,458,045.16 | CC45X 1,914,055.18Y 4,224,546.07 | X 866,242.19Y 2,026,619.67 | 31NE 714,026.60N 5,007,502.10 | Map |
| Bordeaux | 44.8378−0.5792 | L93 X 417,241.54Y 6,421,813.35 | CC45X 1,417,111.35Y 4,188,225.29 | X 369,400.42Y 1,986,174.31 | 30NE 691,334.02N 4,967,783.19 | Map |
| Toulouse | 43.60471.4442 | L93 X 574,357.82Y 6,279,642.97 | CC44X 1,574,404.88Y 3,157,266.85 | X 527,853.02Y 1,845,164.02 | 31NE 374,439.17N 4,829,145.13 | Map |
| Montpellier | 43.61083.8767 | L93 X 770,795.51Y 6,279,476.13 | CC44X 1,770,769.05Y 3,157,136.07 | X 724,498.64Y 1,846,651.39 | 31NE 570,746.62N 4,829,020.08 | Map |
| Marseille | 43.29655.3698 | L93 X 892,390.22Y 6,247,035.26 | CC43X 1,892,264.67Y 2,235,649.15 | X 846,499.55Y 1,815,214.13 | 31NE 692,230.47N 4,796,468.51 | Map |
| Nice | 43.71027.2620 | L93 X 1,043,410.16Y 6,299,400.04 | CC44X 2,043,320.52Y 3,176,675.50 | X 997,226.98Y 1,868,938.58 | 32NE 359,979.95N 4,841,153.92 | Map |
| Ajaccio | 41.91928.7386 | L93 X 1,176,667.56Y 6,108,273.28 | CC42X 2,175,651.96Y 1,206,971.26 | X 1,132,302.32Y 1,678,763.49 | 32NE 478,324.10N 4,640,838.19 | 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 |
|---|---|---|---|---|
| 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 Lambert-93?
EPSG:2154 (RGF93 v1 / Lambert-93). The CC42 to CC50 conformal conics are EPSG:3942 to 3950; Lambert II extended, EPSG:27572; UTM zones 30, 31 and 32 on WGS 84, EPSG:32630 to 32632.
How do I convert GPS coordinates to Lambert-93?
Enter the latitude and longitude — in decimal degrees or degrees, minutes, seconds — in the converter at the top of the page, with “Lambert-93” as the system: X and Y appear at once. Enter X and Y for the reverse. For a list, use the batch conversion and download the CSV.
Which CC zone should I use?
The one whose parallel of origin is nearest the site: CC42 for Ajaccio, CC43 for Marseille, CC45 for Bordeaux, CC46 for Lyon, CC47 for Nantes, CC48 for Rennes, CC49 for Paris, CC50 for Lille. The converter suggests it from the position, and the millions digit of Y plus 41 confirms it.
Why do Lambert II extended and Lambert-93 give such different coordinates?
It is not a simple offset: neither the geodetic system (NTF versus RGF93), nor the meridian (Paris versus Greenwich), nor the projection are the same. Always go through geographic coordinates, as the converter does: pick Lambert II extended, enter X and Y, then switch to Lambert-93.
Can the coordinates be used for a boundary survey?
For locating and checking, yes; for a boundary survey, a division or a cadastral survey document, only a géomètre-expert (chartered surveyor) is authoritative.
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.