Contraction Timer Calculator

About this calculator

Timing contractions turns the raw pattern of a labor into two simple numbers: the interval (time from the start of one contraction to the start of the next) and the duration (how long each contraction itself lasts). Dividing 60 minutes by the interval gives contractions per hour, a simple frequency that tracks how labor is progressing.

A commonly cited guideline for recognizing active labor is the 5-1-1 rule: contractions coming about every 5 minutes, each lasting around 1 minute, sustained for at least 1 hour. It is widely used as a general rule of thumb by expecting parents and childbirth educators to gauge when labor may be advancing, alongside other signs, rather than as a diagnostic threshold on its own.

This calculator only converts the numbers you enter — interval, duration, and count per hour — into a frequency and compares them against the 5-1-1 pattern; it does not assess your specific situation and is not a substitute for guidance from a midwife or obstetrician.