How this calculator works
An event that repeats on a fixed interval has a frequency equal to one over the interval length. The count in a period is the period divided by the interval, rounded down because a partial occurrence at the end does not complete. Changing the units does not change the underlying rate, so one event a minute is the same as one every 60 seconds.
Formula
Let i be the interval in seconds and P the period in seconds. Occurrences = floor(P / i). Frequency per second = 1 / i. Per minute = 60 / i, per hour = 3600 / i and per day = 86400 / i.
Worked example
An event once every second over one day happens 86400 times, which is 60 per minute or 3600 per hour. An event once every 5 minutes over a week happens floor(604800 / 300) = 2016 times, or 288 times a day.
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Frequently asked questions
Are occurrences rounded up or down?
Down. If the period ends partway through an interval, that last occurrence has not happened yet. For planning how many supplies are needed, you may want to round up instead.
Does this assume the first occurrence is at the start?
The count does not depend on where the pattern starts as long as the interval is constant. It is the number of complete intervals that fit in the period, not a calendar schedule with fixed start times.
Why are months and years average lengths?
Calendar months vary in length. The time unit selector uses 30.4375 days for a month and 365.25 days for a year, which are the averages behind the conversion.
Can I model a heartbeat or a fast clock?
Yes, with a realistic interval. At 60 beats per minute the interval is 1 second and one hour holds 3600 beats. The page does not supply medical values; you enter the rate you want to test.