Looking on the internet deeply has found these results:

runtime is the most popular phrase on the web.

running time 113,700,000 results on the web	runtime 1117,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
"Running time 2 minutes, 48 seconds." Trying to get a rough idea of where we are based on speed, running time, and the course correction. The running time of the film is only 78 minutes. Ours is going to be fully stop motion, so I'm trying to make one that's the best quality for a really long running time. Systematic replacement of the device, after a certain running time of the engine, is permissible. "Running time: two minutes. Input, output: 90 minutes." For it to be worthwhile extending plant running time, and hence increasing production, a demand has to exist. The original production of Spoils of Babylon had a running time of 22 hours and was considered...	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

running time

113,700,000 results on the web

runtime

1117,000,000 results on the web

More popular!

"Running time 2 minutes, 48 seconds."
Trying to get a rough idea of where we are based on speed, running time, and the course correction.
The running time of the film is only 78 minutes.
Ours is going to be fully stop motion, so I'm trying to make one that's the best quality for a really long running time.
Systematic replacement of the device, after a certain running time of the engine, is permissible.
"Running time: two minutes. Input, output: 90 minutes."
For it to be worthwhile extending plant running time, and hence increasing production, a demand has to exist.
The original production of Spoils of Babylon had a running time of 22 hours and was considered...

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.