Today, I've added a Yasso calculator. While a Yasso doesn't have to be 'calculated' (just use your marathon hours as minutes and minutes as seconds), but I'd like to know which pace (per km or mile) I should use. I have used the following calculation.
- Kilometer pace: (minutes60+seconds)/8001000 (and revert to minutes:seconds)
- Mile pace: (minutes60+seconds)/8001609 (and revert to minutes:seconds)
So, when your (desired) marathon time is 3:30, you should do a Yasso (800 meters) in 3 minutes and 30 seconds. Using the formula's above, this comes down to a kilometer pace of 4:22 and a mile pace of 07:22.