Triathlon Race Time & Pace Calculator

A triathlon calculator takes the guesswork out of race planning. Whether you are targeting a sprint, Olympic, 70.3, or full Ironman, the ability to predict your finish time from swim, bike, and run paces lets you set realistic goals and pace intelligently on race day. The math is simple but the implications are significant: a 2-minute slower swim translates to 2 minutes on your final time, and a 1 km/h drop in bike speed over 180 km costs you more than 11 minutes.

Triathlon distances at a glance

Sprint: 750 m swim, 20 km bike, 5 km run. Olympic: 1,500 m swim, 40 km bike, 10 km run. 70.3 (Half Ironman): 1,900 m swim, 90 km bike, 21.1 km run. Ironman: 3,800 m swim, 180 km bike, 42.2 km run. The calculator handles all four presets automatically and lets you override any distance for non-standard or modified courses.

Swim pacing in triathlon

Most age-group triathletes swim between 1:30 and 2:30 per 100 m in open water. A 1:50 /100m pace over a 1,500 m Olympic swim takes roughly 27.5 minutes. Wetsuits typically add buoyancy and can improve pace by 3 to 8 seconds per 100 m depending on your technique. Enter your pool pace as a starting point and adjust down slightly for open-water conditions, sighting, and pack turbulence.

Bike pacing and speed

Average bike speeds in triathlon range from 28 km/h for newer sprint athletes to over 40 km/h for competitive Olympic and 70.3 racers. On a flat, windless course with good road surface, a reasonably fit age-group cyclist holds 32 to 35 km/h. Hills, headwinds, and technical corners all reduce average speed. The calculator uses your expected average speed, not your peak, so be honest about conditions on race day.

Run pacing off the bike

Running well after 40, 90, or 180 km on the bike is a skill, not just fitness. Your run pace off the bike is typically 5 to 15 seconds per km slower than your open run pace for the same distance. The calculator does not adjust for this automatically, so enter a realistic off-the-bike pace rather than your standalone 10K or marathon PB. Use the "Required pace for target" mode to see what run pace you need to hold to hit a goal finish time, given your swim and bike splits.

Transitions: the free time

T1 and T2 are the most underrated minutes in triathlon. A 4-minute T1 and 4-minute T2 add 8 minutes to your total, and most of that is avoidable. Practise your transitions. Lay out your gear the same way every time. Elastic laces on your run shoes. A clean T1 of 2 minutes is achievable for most athletes and the calculator lets you factor this in precisely.

Fueling for triathlon

For races over 90 minutes, carbohydrate intake becomes the difference between finishing strong and walking the last 10 km. A high-carbohydrate fueling strategy using dual-transporter carbohydrates lets you absorb up to 90 g of carbs per hour, compared to 60 g from glucose alone. Read more about dual-carbohydrate transporters and why the science is clear. Sodium matters too: most triathletes underestimate how much sodium you actually need and pay for it with cramps late in the run. One serving of Hydrax Core per hour delivers 980 mg of sodium and a 2:1 dual-carb system in 500 ml of water. Take Hydrax Primer 30 to 45 minutes before the swim start to pre-load electrolytes. For longer races, A practical approach to gut training in the weeks leading up to race day is essential to tolerate higher carb intakes. And do not skip carb loading before race day for 70.3 and Ironman events.

To tailor hydration to your body specifically, calculate your sweat rate here using our sweat rate tool. And understand why osmolality matters for performance to avoid the stomach issues that derail so many triathletes mid-race. From there, the Fuelling Strategy Engine converts your split times into an hour-by-hour intake plan, and the Ironman 70.3 nutrition plan and Ironman nutrition plan walk through race-specific execution. Athletes doing heavy bike-run bricks often run HYDRAX CREATINE year-round, and single-serve sachets make special-needs bags simple. When the plan is locked in, build your race kit.

The engine is the same for every mode: time equals distance divided by pace, summed across legs. In Triathlon mode you input swim distance and pace, bike distance and speed, run distance and pace, plus T1 and T2 transitions. The calculator adds them up. In Running and Cycling modes you supply the single leg.

Switch to Required pace for target and the engine works in reverse: enter your goal finish time and it tells you the pace you need to hold. For triathlon, it assumes your swim, bike, and transitions stay as entered and solves for the required run pace.

Pace and distance can be entered in any units (km/mi, m/yd, /100m or /100yd, km/h or mph). Conversion is handled automatically.