Nine converters under one roof. Swim, bike, run pace and speed conversions; temperature guidance for what to wear; weight and height in any unit; fluid volumes; RPE descriptions; and the carb-concentration calculator that tells you whether your bottle is going to wreck your stomach.
Choose the type from the dropdown. Type a value into the field you want as the source, then hit Calculate, the rest of the fields fill in.
Click in one field, type your data, press Calculate to fill the others.
Click in the field you want as “driver,” then press Calculate.
Click in one field, then press Calculate.
Type Celsius or Fahrenheit, press Calculate to update + show what to wear.
Pick one field, type a number, press Calculate.
Focus one field, type a number, press Calculate.
Type a number in one field, press Calculate.
Enter RPE (1–10), then click Calculate.
Compute the concentration (by weight) of a solution, carbs, salt, anything, plus the approximate %. Useful for checking whether your custom drink mix is going to sit in your stomach.
Three real moments where this saves you a calculator app and a unit-conversion screw-up.
Plug 4:30/km into the run section, hit Calculate, you get min/mile, m/s, km/h, mph, and finish times for 5K, 10K, half, and marathon at that pace. No mental math at the start line.
Type the water temp in the temperature section to see wetsuit rules. Same panel covers what to wear on the bike and run from heat-stress hot to balaclava-cold.
The concentration calculator tells you the % carb of a custom mix, under 4% is too dilute, over 8% will sit in your stomach. Your race-day fueling depends on getting this right.
This tool is good at one thing: making the same number readable in any unit. It will not tell you whether 4:00/km is your pace today, whether 28 °C means you should change race-day fueling, or whether your 10% carb drink is the right call for a 70.3.
For those calls, you need a coach who knows you and a lab measurement that grounds the targets, threshold, FTP, fat-oxidation rate, sweat rate. Without that, you’re converting numbers in a vacuum.
One running effort in, finish times across 1.6 km to marathon.
Open → Intra-workout fuelingPairs with the concentration tab, total carbs/hour, food equivalents, DIY ratios.
Open → All calculatorsBack to the full catalog, 30+ endurance calculators across performance, fueling, swim, bike, run.
Browse →Conversions tell you 4:30/km in another unit. Lab testing tells you whether 4:30/km is sustainable, what fuel you need at that intensity, and where your physiology breaks. Skip the guessing.
Spotted a bug or want a feature? Email info@yousuli.co.
