Transport 

The Paris public transport system, known by the acronym RATP, is one of the world's most comprehensive and efficient. It includes the Métro, the (mostly) underground rail network covering the entire city, and the RER (light suburban rail) and bus systems. For pricing purposes it is based on eight "Zones" essentially concentric circles.

Zones 1 and 2 comprise the 20 numbered arrondissements of Paris proper. There are 14 Métro lines, numbered (logically enough) from 1 to 14, and 5 RER lines designated by the letters A though E. A Zone map and Métro and RER maps can be found at: http://www.ratp.info/informer/anglais... Nowhere within Paris will you ever be more than a very few hundred meters from a Métro station.

The interactive map on the RATP site works well, and is easy to use once you get the hang of it. Try it, you might like it: http://www.ratp.fr/plan-interactif/ca...

If you are coming to Paris on Eurostar or Thalys trains you can buy métro tickets and passes at a small premium in the bar car on board the trains. You can also buy them at St. Pancras station in London. 

Note that most of the links below are to the French-language version of the RATP site. The English language version, while useful, does not contain much of this information. 

Individual transport tickets and carnets

Prices quoted below are from RATP website and valid from July 2014

A single-use Métro/bus "Le ticket t+" costs €1.70.

 A "carnet" (karn-ay) of 10 single-use tickets costs €13.70.

Carnets can be purchased on arrival at Charles de Gaulle Airport from French Tourist Information Desks in Arrivals.

Individual tickets and Carnets of tickets can be used any time, even months after they were purchased. Keep them (and all passes) away from magnets and cards with magnetic strips.

Note that you should keep your ticket until you leave the system. Periodic spot checks occur, and substantial on-the-spot fines are given for failure to produce a vaild ticket. In addition, you cannot exit through the turnstiles on the RER system without a valid ticket. To summarize, within Paris proper, ANY individual ticket, and ANY pass covering at least Zones 1 and 2 is valid on ANY Métro or RER train, any bus, including night buses, and on the Montmartre funiculaire.

Multi-use transport passes

Prices quoted below are from RATP website and valid from January 2014

For most visitors the choices of Métro/bus/RER passes boil down to three: the reloadable Navigo card (which replaced the old Carte Orange), the Mobilis pass, and the Paris Visite pass. They vary in their period of validity and in price.

There is no reduction in price on any of these tickets or passes for seniors. Multi-day Paris Visite passes are valid for CONSECUTIVE calendar days starting with the day of their first use. The Paris Visite and under-26 passes are NOT available for Zones 1 & 2 only. All these passes are valid on any transport modality on the RATP system within the Zones they cover. Except for the 5-day Paris Visite pass, multiple one-day Zone 1 & 2 Mobilis passes are actually a better buy for most people, since most visitors do not travel outside Paris proper except when travelling from/to the major airports or to sites outside Zone 3. Mobilis passes are not valid for travel between Paris and either CDG or Orly by the most commonly used public transport routes.

All these passes only make economic sense if you are using the transport system enough to justify the extra cost when compared with buying a Carnet or individual tickets. The various passes do of course offer the non-monetary benefit of "one stop" shopping. The Paris Visite pass comes with a "basket" of fringe benefits that are not available with any other transport pass. For a full list of these offers, look at ArrowCapet's excellent post: http://tinyurl.com/zz2yj 

Mobilis 

With Mobilis, you can travel unlimited in selected areas. You can move on all modes of Île-de-France, Metro, RER Bus, Tram and Train except Filéo, and Voguéo routes serving airports (Orlyval Orlybus, Roissy, Orly and Roissy by RER). Access by lines 183 and 285 to Orly airport and lines 350 and 351 to Roissy is possible (for affected areas). 

Zones  Price
 1-2€  6.80
 1-3€  9.05
 1-4€ 11.20
 1-5€ 16.10

Multi-day Mobilis passes are not sold.

Paris Visite 

Paris Visite is a valid for 1, 2, 3 or 5 consecutive days in Paris center (zones 1-3) or Paris center, suburbs and airports (zones 1-5). 

Number of days

 Zones 1-3 

 Zones 1-5 
  "Paris Centre" "Paris Banieue"
1 € 10.85 € 22.85
2 € 17.65 € 34.70
3 € 24.10 € 48.65
5 € 34.70  € 59.50

Children get a 50% discount on these prices.

For most travelers, the Paris Visite passes are not a cost-effective option unless the discounts and offers that are bundled with the card are used. It is a simple matter to purchase the Paris Visite pass on arrival in Paris and there is really little or no benefit to paying a premium to purchase it in advance. Some travelers do not want to waste time to figure out where to buy it (more than 100+ metro stations without staff) and have it in hand before arriving in Paris, such service can be found with Paris Concierges.

Details of the Paris Visite passes can be found here: http://www.ratp.fr/en/ratp/c_22088/pa... 

Ticket Jeunes Week-end

A special one-day Zone 1-3 pass for those aged under 26, the Ticket Jeunes Week-end is valid ONLY on Saturdays, Sundays and public holidays.

Zones 1-3 costs €3.65

Zone 1-5  €8.10

 Zone 3-5 €4.75

Navigo Card

The Navigo pass is a reloadable "smart card" valid for 10 years and costing €5. It can be loaded with a weekly pass valid from Monday through the following Sunday or a monthly pass valid for one calendar month. The Navigo pass is valid within the zones covered by the pass on the métro, RER, buses, tramways and SNCF commuter trains that do not require a reservation. The card is swiped from your purse or wallet over a proximity reader. The Navigo pass loaded with a weekly pass may be  the best deal if its validity coincides with your itinerary. The validity of the weekly pass runs from the first train on Monday morning to the last train on Sunday night. It is the most cost-effective pass. However, it is intended primarily for residents and so presents some problems to visitors, as both its use and its sale are limited to specific days. The Navigo pass for the current week is available through Thursday of that week, and sale of the pass for the upcoming week begins on Friday. So you need to take into account your day of arrival, and your likely use of the Métro/buses to decide if it wil lwork for you.  If you intend to purchase a Navigo card, you will need a passport-type photo, approximately 2.5cm by 3 cm. 

The prices for all Navigo pass (formerly Carte Orange) passes are shown here: http://www.ratp.fr/fr/ratp/c_21137/fo...

Getting to and From the Airports by RER Trains

RER tickets to/from CDG (Zone 5) cost €9.50 one-way, €19.00 round trip.

One-way RER tickets to/from Versailles (Zone 4) cost €4.00 adult and €2.00 child.

One-way RER tickets to/from Disneyland (Zone 5) cost €8.30 adult and €4.20 child.

If you plan on making all of these trips, or several other trips outside the central (Zones 1 & 2) areas, a weekly Navigo pass or the appropriate Mobilis or Paris Visite pass for Zones 1-5 might be your best buy. Not listed are the options for the Zone 1-5 and other passes since MOST people will not find them cost-effective.

Finally, some basic information on travelling between central Paris and Orly and CDG airports using public transport can be found here: http://www.transilien.com/static/tour... (in French).


Museum Passes

The Paris Museum Pass provides unlimited access during its period of validity to more than 60 museums and monuments in and around Paris. Besides its convenience, it can save considerable amounts of time by permitting you to by-pass long ticket lines.

Museum Passes can be purchased on arrival at Charles de Gaulle Airport from French Tourist Information Desks in Arrivals (Terminals 1, 2C, 2D and 2F) and at Orly airoport (Terminals South and West). 

Current Paris Museum Passes (July 2014) are for 2, 4 or 6 consecutive days, costing €42, €56 and €69 respectively. Whether the Museum Pass makes sense is a function BOTH of the number of museums you intend to visit AND of the value you place on the time you can save by using the Pass to by-pass sometimes lengthy ticket lines.

Another benefit is that the Pass permits multiple visits to any covered museum, as well as permitting you to just duck into a museum for a quick look round (or to use the "facilities"...) without having to pay the entrance fee. I'd figure an average of around €9 - €15 per museum if you want to calculate the purely monetary cost-benefit ratio of the pass. 

Full information about the Paris Museum Pass is available at the ONLY OFFICIAL site "Paris Museum Pass" (www.parismuseumpass.com). All the sales points of the pass are fully detailed here. Note that you can directly buy the pass in the first museum you're visiting, and that American (magnetic strip) credit cards will not work in automatic ticket machines such as those found at CDG.

The pass can be pre-ordered as redeemable voucher, or sent to your home in advance by several third-party vendors such as Hello Paris (UK), Museumpass, or Conciergerie.com, but please note that it is ALWAYS more expensive to buy any of these products from third-party vendors before arriving in Paris. There is therefore little point in paying a premium for a product that can be easily purchased on arrival in Paris but those who have little time may consider to buy the service to have it delivered to home or the hotel in Paris.

Note that the "Paris Museum Pass" and the "Paris Pass" are two different products, which do not include the same activities and services, so be sure to choose the one that most suits your needs and your budget. Especially as the Paris Museum Pass is often integrated into the services and packages offers by travel agencies and touristic companies. The Paris Pass essentially bundles the Paris Museum Pass with the Paris Visite passes and bundles some superficially attractive discounts and "free" offers to make the whole package more marketable. Most people will find that the Paris Museum Pass combined with the most cost-effective transportation option, usually NOT a Paris Visite pass, will serve their needs as well as or better than a Paris Pass at a considerably lower cost. The Paris ComboPass® is also a cheaper alternative with Lite and Premium versions.

If you stay for a few weeks in Paris and want to see the Louvre five or more times its worth it to become a Friend of the Louvre (Société des Amis du Louvre) for 60€ for one or 90€ for a couple. This gives a year of unlimited free entries to the Louvre (normally 9.50€ a visit) as well as the special exhibitions (11€ each). The membership gives priority access as well as discounts and/or free access to other museums in Paris as well as discounts at shops and restaurants in the Louvre. This Friends pass can be bought in the Louvre behind the information desk in the Carousel near Starbucks.

If you want to convert from Euros to a currency you are more familiar with try: http://www.xe.com/  For more info go to: www.ratp.fr http://www.parismuseumpass.com/ http://www.transilien.com/FR/ http://parispasses.net

**Note: This original source of this information was from the TripAdvisor forums thread: http://www.tripadvisor.com/ShowTopic-...