The numbers, explained.

Pace is time per unit of distance. A 5:00/km pace means each kilometer takes five minutes. Speed measures distance per hour. The pace calculator converts between both and includes swimming units.

The race is divided into two equal-distance halves. At the default 2% setting, your first-half pace is 2% slower than average and your second-half pace is 2% faster. You spend 51% of your goal time in the first half and 49% in the second. Your total goal stays fixed.

These tools calculate a plan from the goal you choose. They do not assess fitness or predict performance. The plan does not account for terrain, weather, traffic, or stops.

Distances and times retain precision internally. Cumulative checkpoints are rounded to the nearest second; individual split times are then calculated from those rounded checkpoints so they add up to your finish goal.

Use minutes:seconds, such as 45:00, or hours:minutes:seconds, such as 1:45:00. Seconds must be 00–59. For the three-part format, minutes must also be 00–59. Durations above 24 hours are supported.

Watts per kilogram is your power output divided by your weight in kilograms. 240 watts at 75 kilograms is 3.20 W/kg. Compare power measured over similar durations and conditions.

A short effort, a 20-minute average, and an FTP estimate represent different things. The calculator labels your chosen context without converting one into another. It does not infer FTP or predict riding speed.

It solves the equation weight = watts ÷ W/kg. This is an algebraic conversion, not a recommendation to change your body weight.

One mile is 1,609.344 meters, one yard is 0.9144 meters, and one pound is 0.45359237 kilograms. Half-marathon and marathon presets use 21,097.5 and 42,195 meters, respectively. Entering 13.1 or 26.2 miles is a slightly different distance.

Plans, drafts, and preferences stay in this browser on this device. No account or cloud sync is required. Use Backup in My plans to download your plans as a JSON file, then import it on another device.

The link contains your race distance, goal time, strategy, and display units. It does not contain your plan name, local ID, or cycling weight. Anyone with the link can open a copy.

The PNG pace card is a compact summary with four useful checkpoints. The printable pace band lists cumulative times for your selected split spacing, across numbered strips when necessary. Use Print full sheet for all segment details.

New plan IDs are added. IDs already on this device are skipped, so an import will not overwrite an existing plan. Invalid or unsupported files are rejected as a whole.