Hi,
The Stryd race calculator is a paid feature - as I don't really need any other of the features, it seems excessive to pay 100 USD/year only for the calculator. Is there any other way to calculate the data needed?

Here's some information I found, maybe this is helpful?
https://hetgeheimvanhardlopen.nl/en/translate-your-workout-description-in-running-power-yourself/

We give an example how you can easily calculate the wattage with which you have to run according to your work-out scheme: Suppose you have to run a block in 10 K race pace. You weighs 70 kg and runs the 10 K in 50:00. The scheme then actually requires a pace of 5:00/km. Over 1000 meters (1 km) this is 300 seconds (5:00), so 1000/300 = 3.33 meters/second.

The` wattage (power) with which you have to run that particular block can be calculated as:

3.33` m/s1.0470 kg = 242 Watts.

Another` task could be to run a 400 meters in 28 seconds per 100 meters.

This requires a running speed of 100/28 = 3.57 m/s.

Your corresponding wattage is 3.57 m/s1.0470 kg = 260 Watts.

This` way you calculate for all situations the wattage that you have to run. Whether you need to run an endurance run, blocks, or intervals over a certain distance or duration.

There's some information and formulas here:
https://www.georgeron.com/2017/12/stryd-running-power-model.html

Does this help?