How to use
- Enter the inputs.
- Sanity-check the outputs.
- Use the result as a planning anchor, not a promise.
Jump to
Tool
Inputs → outputs
This page is intentionally practical: get numbers first, then read the how-to.
Inputs
- • Race
- • Swim pace (per 100m/100yd)
- • Bike speed (km/h or mph)
- • Run pace (per km/mi)
- • T1 (mm:ss) (optional)
- • T2 (mm:ss) (optional)
Outputs
- • Finish time estimate
- • Swim total
- • Bike total
- • Run total
- • Transitions total
Export
Print or share the tool
Useful outputs beat generic SEO copy. Print a PDF or share this page before race week.
Tip: print or save as PDF for race week.
Example presets
Prefill with a realistic scenario
Pick an example to prefill the calculator, then tweak inputs for your own training week.
Loading 70.3 time calculator…
Quick answers
The 60-second version
Snippet-ready answers to common questions. Use the calculator above for the numbers.
Should I use pool pace or open-water pace?
Use something closer to open-water effort. Pool paces often overestimate open-water speed due to turns, drafting differences, and conditions.
Is bike average speed realistic?
Be conservative. Wind, elevation, and nutrition can lower average speed. Use the estimate to plan, then refine after long rides on similar terrain.
Why does the run estimate feel slow?
Most athletes run slower off the bike than on fresh legs. If your estimate is optimistic, that’s a sign to tighten pacing and fueling execution.
Assumptions
What this tool assumes
- • Distances are standard (70.3: 1.9 km swim / 90 km bike / 21.1 km run; Ironman: 3.8 km / 180 km / 42.2 km).
- • Swim pace is based on a sustainable open-water effort (not a pool sprint).
- • Bike speed is a realistic average including course profile and conditions.
- • Run pace reflects what you can hold off the bike (not a fresh standalone half/marathon pace).
Limitations
What can break it
- • Does not account for course elevation, wind, heat, or aid-station slowdowns.
- • Open-water conditions and traffic can meaningfully change swim time.
- • Nutrition mistakes can destroy the run; use the estimate as a baseline, not a promise.
Related
Use this with a plan
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FAQs
Should I use pool pace or open-water pace?
Use something closer to open-water effort. Pool paces often overestimate open-water speed due to turns, drafting differences, and conditions.
Is bike average speed realistic?
Be conservative. Wind, elevation, and nutrition can lower average speed. Use the estimate to plan, then refine after long rides on similar terrain.
Why does the run estimate feel slow?
Most athletes run slower off the bike than on fresh legs. If your estimate is optimistic, that’s a sign to tighten pacing and fueling execution.
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