New to IRC?

Are you are considering IRC racing but don’t know where to start with getting a rating, or what is involved? Perhaps you have friends who race IRC, or your club has just introduced an IRC class?

To dispel a common misconception that IRC is only for serious racers, this is not the case. IRC rates all types of boats from dayboats through to large heavy classics, and every type in between!   We recognise that the process of getting a rating can appear tortuous, but we aim to help you find your way through it...

If you are new to any sort of yacht racing, have a look at the RORC article about how to start racing.


On this site you can find  Frequently asked Questions, rules and regulations and additional information, advice to race organisers and other information which applies worldwide.  We have Rule Authorities (IRC 'agents') in a large number of countries worldwide, so the first thing to do is look HERE to see if there is a contact for your country.

The IRC 2018 yearbook is available online via the link on the homepage of this site (scroll down to find it). In the Yearbook you can find editorial, the IRC Rule and a great deal of information and advice.  If you would like a hard copy please contact your Rule Authority who will be able to send you one. 


There is no substitute for the full IRC rule to make sure your boat complies, and you can find these in the Technical/Admin section of this website; however there are simplified rules that cover the basics, on the RORC Rating Office website HERE.

Help with measurements:

For production boats we are likely to hold standard hull data, that is the length, beam, draft, weight and bow and stern overhangs.  That means that we only need the rig and sail measurements, plus the additional details which are specific to your boat, such as furling headsails and propeller type.  It probably seems tedious having to give us all the details of your boat, but it means that the rating will reflect your specific set-up.

You can find some simplified measurement guidance on this site. This section is a work in progress so if you have any ideas for other 'simplified guidance' that is not already covered elsewhere on this site, please e-mail , thank you.

If you prefer a measurer to come and help then your Rule Authority can arrange that too.  The measurement page HERE gives lots of advice about how to measure to the IRC Rules.

We're here!

Once you have had a browse around the sites, if you have more questions please talk to your Rule Authority, or use the contact form on this site if you are in a Country without a Rule Authority.

RORC Rating Office & UNCL Centre de Calcul


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The Rating Rule for ALL

What is so great about it?

  • Rate your standard production cruiser/racer, classic or hi-tech racing yacht
  • Great racing inshore and offshore 
  • From small local events to major national trophies
  • Use the same rating in any event worldwide with an IRC class
  • No local handicap adjustments
  • Simple to calculate corrected time and position while on the water
  • Single number, time-on-time rating (TCC) 
  • Calculated from basic boat data and configuration details
  • Physical weighing and measurement by your local IRC measurer, if required
  • Ability to run trial ratings to test effect of proposed changes
  • Simple to amend rated data during the year
  • Progressive approach to the rating of technical developments
  • Allowances for full fitout and cruising features

OK, but please can you explain the basics...?

IRC is a rating rule
IRC is a rating rule to handicap different designs of keelboats allowing them to race together; unlike a performance handicap a rating is not altered between races according to the individual boat's performance, but is based on the physical measurements of the boat. 

Each boat’s rating (her ‘handicap’) is calculated using measurements of the boat; her length, weight, draft, rig size, sail area, and specific characteristics and features. The resulting time corrector, the boat’s ‘TCC’, is her handicap. The higher the TCC figure, the faster the boat's potential speed; IRC TCCs range from 0.750 to 1.900, with the majority of cruiser/racers between 0.900 and 1.100.

After a race, each boat’s elapsed time (the time she has taken to complete the course) is multiplied by her TCC to calculate her corrected time (her race time making allowance for the characteristics of the boat). The boat with the shortest corrected time is the winner of the race.

IRC is for keelboats of all size and shapes
IRC is aimed at a very wide range of keelboats of all sizes and shapes including modern production cruisers and cruiser/racers through dedicated one-off race boats, older cruisers and racers to classic yachts and superyachts. IRC is continually developed to encompass new developments in both cruisers and racers while at the same time protecting the interests of the bulk of the fleet.

IRC is a permissive rule
It is open to all types, sizes and ages of boats. IRC permits features such as asymmetric spinnakers, bowsprits, twin, triple, wing and drop keels, twin masts, gaff rigs, water ballast, canting keels, ‘code zero’ headsails, lateral daggerboards etc., and deals with these features as equitably as possible.

IRC is an unpublished rule
The methods and formulae used for the calculation of IRC TCCs are not published. This prevents designers taking advantage of the rule when designing new boats and very substantially increases the competitive lifetime of IRC rated boats. As a result, boats of all ages and types win races under IRC. Everything from classics through IOR designs to modern cruisers, cruiser/racers, and racers.

IRC is a simple rule
IRC is structured to be as simple as possible for both sailors and race administrators: there is no requirement for boats to be officially measured (unless required in individual countries). IRC accepts owner declaration of a boat’s measurements. All an owner needs to do is fill in the application form and send it to us. There is the option of an 'Endorsed' certificate, for which the data has been audited which may include official weighing and measurement.

IRC is popular
IRC is used for a huge number of races and regattas all over the world, and it would be impossible to list them all!   As a taster, apart from local club races IRC is used at (among many others) well known events such as: Round the Island Race (UK), Lendy Cowes Week, Rolex Fastnet Race, Volvo Cork Week, RORC Caribbean 600, Voiles de St Tropez, Rolex Middle Sea Race, Rolex Sydney Hobart Yacht Race, Japan Cup, Hamilton Island Race Week, Rolex China Sea Race,  Phuket King's Cup, Giraglia Rolex Cup, Spi Ouest France, NYYC Annual Regatta, Maxi Yacht Rolex Cup and Mini Maxi Rolex World Championship, Volvo Dun Laoghaire Regatta, Half Ton Classics Cup, Quarter Ton Cup, Marmaris Week, Block Island Race Week, Australian Yachting Championships, RORC Commodores' Cup, Transatlantic Race, IRC European Championship, IRC North American Championship, and various national championships. (Event sponsors as at Feb 2018).

Last year nearly 7000 boats in 30+ countries on all 6 continents held IRC certificates.

All the technical information needed to apply for an IRC certificate can be found on this website. Application forms are available from your local IRC Rule Authority.

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Header images by:

John Crawley (CAN IRC)  
Jinno (c/o JPN IRC)
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