What can this race calculator do?

It predicts finish times for triathlon (sprint, Olympic, 70.3, Ironman), running (5K to marathon), and cycling. You can also work backwards from a target time to find the pace or speed you need. Switch between modes using the tabs above the calculator.

Can I use different units?

Yes. The calculator supports km and miles for distance, per-100m and per-100yd for swim pace, per-km and per-mile for run pace, and km/h and mph for cycling speed. All conversions are handled automatically.

How accurate are the predictions?

The math is exact for the inputs you provide. Real-world results vary with conditions like wind, terrain, heat, and your own pacing decisions. Use the calculator as a planning tool and adjust based on what you know about the course and conditions.

How do I factor in fueling for long races?

For events over 60 to 90 minutes, carbohydrate and sodium intake becomes critical. The calculator shows an estimated fueling recommendation based on your predicted duration. One serving of HYDRAX CORE per hour delivers 980 mg of sodium and a 2:1 dual-carb system. Take HYDRAX PRIMER before the start to pre-load electrolytes.

Tools

Race Time & Pace Calculator

Predict your finish time or work out the pace required to hit a target. Triathlon, running, or cycling.

Swim

Distance

Pace

Bike

Distance

Speed

Run

Distance

Pace

Transitions

T1 (swim → bike)

T2 (bike → run)

Result

Estimated finish time

2:36:30

Swim

0:27:30

0:02:00

Bike

1:15:00

0:02:00

Run

0:50:00

Fueling for this race

At an estimated 2:36:30, plan for approximately 3 servings of HYDRAX CORE across the session (one serve per hour as a starting point), plus 1 serve of HYDRAX PRIMER 30–45 minutes before the start.

Build a full fueling plan →

This all-in-one race calculator covers triathlon, running, and cycling in a single tool. Switch between modes using the tabs above. Every mode uses the same engine: time equals distance divided by pace, summed across legs. You can predict a finish time from your paces or work backwards from a target time to find the pace you need.

For triathlon, enter your swim, bike, run, and transition times to get a total race time. For running, enter distance and pace. For cycling, enter distance and average speed. All units are supported and converted automatically.

For events over 60 to 90 minutes, carbohydrate and sodium fueling becomes the deciding factor in whether you finish strong or fade. A high-carbohydrate fueling strategy using dual-carbohydrate transporters lets you absorb more energy per hour. Take Hydrax Core during the race and Hydrax Primer before the start. Read about how much sodium you actually need, understand why osmolality matters for performance, and calculate your sweat rate here to personalise your hydration. For longer events, A practical approach to gut training and carb loading before race day are essential preparation.

Once you have a target time, turn it into a plan with the Fuelling Strategy Engine, then match it to your event: the marathon fuelling plan, the Ironman nutrition plan, the Ironman 70.3 nutrition plan or the HYROX fuelling guide. Runners can start with endurance fuel for runners. Training between races is where HYDRAX CREATINE earns its place, and single-serve sachets keep race-day dosing simple. When your numbers are set, build your race kit.

Cycling speed & time reference

How long common cycling distances take at different average speeds.

Goal time	5K pace	10K pace	Half marathon pace	Marathon pace
20:00	4:00 /km	4:11 /km	4:15 /km	4:15 /km
25:00	5:00 /km	5:14 /km	5:19 /km	5:20 /km
30:00	6:00 /km	6:17 /km	6:23 /km	6:24 /km
40:00	8:00 /km	8:22 /km	8:30 /km	8:32 /km
45:00	—	4:30 /km	4:35 /km	4:36 /km
50:00	—	5:00 /km	5:05 /km	5:07 /km
1:30:00	—	—	4:16 /km	4:17 /km
1:45:00	—	—	4:59 /km	5:00 /km
2:00:00	—	—	5:41 /km	5:42 /km
3:00:00	—	—	—	4:15 /km
3:30:00	—	—	—	4:58 /km
4:00:00	—	—	—	5:41 /km

Frequently asked questions

How this works

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.

This tool provides an educational estimate based on the inputs you provide. Real race times are affected by elevation, wind, drafting, nutrition, pacing strategy, and individual physiology. Use it as a planning aid, not a guarantee.

Disclaimer: This page is general information for healthy adult athletes and is not medical, dietetic or coaching advice. Individual carbohydrate, fluid and sodium requirements vary with body weight, sweat rate, conditions and health status. Speak with your doctor, sports physician or an accredited sports dietitian before changing your nutrition or supplement routine, rehearse any fuelling plan in training before race day, and always follow the directions and warnings on the product label.