I originally made this calculator to give my sprinters accurate goal times in their workouts. Since then I have found it to be equally useful with middle and long distance runners.
Inputs are bold black. Outputs are red.
Fill in a relevant race distance in meters. Fill in that race time in seconds. Fill in interval speed at the desired intensity (example: for 80%, type in 0.8). Finally fill in the interval distance in meters. The time you should run your intervals in will appear in red.
Below the main calculator you'll find a quick and easy way to estimate 300 meter race times. Simply fill in recent 200 and 400 meter race times and your 300 meter race time will appear in red. While over-simplified it is surprisingly accurate.
The final section of the calculator is a weekly mileage calculator. You'll find this to the right of the main calculator. Inputs are bold black and output is red. Simply enter the number of days in your training cycle, along with the miles covered in that cycle, and you'll see how many miles per week you're covering. (example: 10 day cycle, 70 miles total = 49 miles per week)
I originally made this calculator to see if more complex conversion formulas held up in real world conditions. So I compiled data from many of the world's greatest milers and found that my calculator produced nearly identical output to those already out there. So the mathematic and physiologically based formulas seem to match real world conditions.
Inputs are yellow. Outputs are red.
Scroll to the bottom of the page. There you will find yellow input cells for 1500, 1600 and mile. Simply input a time in minutes and seconds. Your converted time for the other two distances will show in the same row in red. The output times are in seconds not minutes and seconds.