The quick and simple time lapse calculator to know how long time lapses are

How long is a 27 seconds timelapse iphone?

There's no real way to know. Time lapses in iPhones are sped up automatically so the final time-lapse video always end up being between 20 and 40 seconds, no matter how much real time was recorded. What we know is that if this was a regular timelapse movie, if you record for 27 seconds, you'll get a time lapse 0 seconds long. On the other hand, 27 seconds of time-lapse video represent about 27 minutes of real time
(assumming the time-lapse video was shot at an interval of 2 seconds every frame and reproduced at 30fps)