Triathlon distances: every UK race distance explained

Triathlon distances in the UK range from the super sprint (250 m swim, 10 km bike, 2.5 km run) to long distance (up to 4 km, 200 km and 42.2 km). British Triathlon recognises five formats. The standard distance of 1500 m, 40 km and 10 km is the one most people call Olympic.

This guide sets out every distance in the British Triathlon Competition Rules 2026, the minimum age for each one, the same figures in miles, and a simple way to pick the right distance for your first or next race. Each distance then has its own guide with UK race examples.

British Triathlon distances and minimum ages

The table comes from Appendix A of the British Triathlon Competition Rules 2026 (April 2026 version), which cover races in Great Britain held under British Triathlon rules. The minimum age is your age on 31 December of the race year, so a 14-year-old whose 15th birthday falls in November counts as 15 for the whole season.

Two details are worth noticing. The sprint has two versions: a pool sprint with a 400 m swim and an open-water sprint with a 750 m swim, while the bike and run stay the same. The middle and long distances are written as maximums, with a "traditional" distance given alongside. The UK half and full-distance races in our guides use those traditional figures or their equivalents in miles.

Triathlon distances in miles

Many UK organisers, especially at middle and long distance, publish their courses in miles. These conversions are rounded.

The middle-distance figures explain the name of one well-known race series: 1.2 + 56 + 13.1 miles adds up to 70.3 miles. The run legs of standard and middle distance are the same as a 10 km road race and a half marathon, and the long-distance run is a full marathon.

Standard or Olympic? UK names for each distance

The same race can appear under different names depending on who is talking. These are the names you will meet on UK entry pages.

• Super sprint. The shortest individual format. Supertri writes it as one word, SuperSprint, for its races at Blenheim Palace.
• Sprint. The usual first race. In a pool the swim is shorter (400 m under British Triathlon rules); in a lake, river or dock it is normally 750 m.
• Standard or Olympic. Standard is the term British Triathlon uses. Race websites often say Olympic for the same 1.5 km, 40 km and 10 km race.
• Middle, half or 70.3. Middle is the rulebook word. Athletes often say half distance or half ironman. IRONMAN 70.3 is a branded series of middle-distance races, and the Outlaw Nottingham Half is a non-IRONMAN race over the same 1.2, 56 and 13.1 miles.
• Long or full. Often called full distance. The Outlaw full-distance race in Nottingham lists a 2.4 mile swim and a 112 mile bike.

Why a race's distances may not match the table

Organisers design their own courses around a venue, so a sprint in one place can be a kilometre or two longer or shorter than a sprint elsewhere. Some examples from organisers' own pages, checked on 6 October 2026:

• Supertri Blenheim Palace lists its sprint as 750 m, 19.8 km and 5.4 km, and its SuperSprint as 400 m, 13.3 km and 2.9 km.
• The London T100 super sprint uses a 400 m swim, longer than the 250 m in the British Triathlon table, with a 10 km bike and 2.5 km run.
• The Thames Turbo Sprint Triathlon, a club-run pool race in Hampton, uses a 432 m swim, 21 km bike and 5 km run.
• Royal Windsor Triathlon gives its sprint bike as 20 km in the event description and 22 km in the course text.
• The London T100 also runs an age-group race over 2 km, 80 km and 18 km, a format of its own between standard and middle.

Read the course page before you enter. Differences on the bike or run change your finishing time a little. Differences on the swim matter more, because swim length decides which wetsuit rules apply and how long you spend in cold water.

Wetsuit rules depend on swim distance

British Triathlon links wetsuit rules to water temperature and swim length. For swims up to 1500 m, a wetsuit is mandatory below 15.9 °C. It is forbidden above 22 °C if you are 59 or younger, and above 24.6 °C if you are 60 or older. For swims of 1501 m or more, the upper limit is 24.6 °C for all ages. Your age is again counted at 31 December.

Cold water also shortens the swim itself. Below 11 °C there can be no open-water swim in competition. At 13 °C the maximum swim is 1000 m, at 12 °C it is 600 m and at 11 °C it is 300 m. The temperature is taken one hour before the start. If you enter an early-season standard race, it is possible that the 1500 m swim is cut short on the day. Our guide to British Triathlon rules for UK races covers wetsuits, drafting and transition in more detail.

How to choose your triathlon distance

There is no single right order, but most people build up one step at a time. Think about three things: how comfortable you are in the water, how many hours a week you can train, and how long you want to be racing on the day.

If you have never raced

Start with a sprint. If open water worries you, a pool sprint lets you swim lengths in a lane with a wall close by, and you can do your first open-water race later. A super sprint is a shorter taster and suits people who want to try the format with less training. Our triathlon guide for beginners explains what to expect from entry to finish line.

If you have done a sprint

The standard distance doubles the swim, bike and run of an open-water sprint. The extra swim is the biggest change for most people to 1500 m in open water, where the wetsuit rules for swims up to 1500 m still apply. You need to be 17 under British Triathlon rules. See our Olympic triathlon guide for UK races and what changes from sprint.

If you are thinking about middle or long distance

Middle distance (minimum age 18) and long distance (minimum age 19) are a different kind of commitment. The race takes most of a day and the training takes months, with long rides at weekends. Many people race sprints and standards for a season or more first. Our half ironman guide for the UK lists middle-distance races with confirmed dates.

If swimming is what holds you back

A duathlon replaces the swim with a first run. The British Triathlon sprint duathlon is 5 km run, 20 km bike and 2.5 km run. An aquathlon is the opposite: swim and run with no bike. Both are a good way to learn transitions and pacing. See duathlon and aquathlon distances for the full list.

A note on time and age-group racing

Most people who enter UK triathlons are age-groupers: amateur athletes who race in age categories rather than as professionals. Whatever the distance, you race your own race. Finishing times vary widely with swim ability, bike and course, so treat any time you read online as a rough guide only.

Before you enter, check three things on the organiser's website: the exact distances, the minimum age, and whether the swim is in a pool or open water. If you have a medical condition or have been inactive for a while, see your GP before starting hard training for any distance.

Guides to each distance

• Sprint and super sprint triathlon: pool and open-water sprints, and UK races to start with.
• Olympic (standard) triathlon: 1500 m, 40 km, 10 km, wetsuit and drafting rules.
• Half ironman and middle distance in the UK: 1.2, 56 and 13.1 miles and the UK races.
• Duathlon and aquathlon: run-bike-run and swim-run formats.

Frequently asked questions