Timing contractions: what the numbers actually mean

“Time your contractions” is common advice, but it’s worth being clear about what those numbers actually represent, and what they don’t. Timing contractions produces two pieces of information, duration and frequency, and reading them correctly is more useful than watching either number in isolation.

Duration: how long one contraction lasts

Duration is the length of a single contraction, from when it starts (the uterus begins tightening) to when it ends (it relaxes again). It’s typically measured in seconds. A contraction’s duration can change over the course of labor, and tracking it over several contractions, rather than judging by one, gives a clearer sense of the trend.

Frequency: the time from one start to the next start

Frequency is easy to mismeasure because it’s commonly, and incorrectly, thought of as the gap between contractions. It’s actually measured from the start of one contraction to the start of the next one, which includes both the contraction itself and the rest period after it. This site’s Contraction Timer logs the start time of each contraction specifically so this number is calculated correctly rather than estimated.

A commonly cited general pattern as labor progresses

A widely referenced general pattern, though not a universal rule that every labor follows exactly, is that contractions tend to become more regular, closer together, and longer-lasting as labor progresses. Early on, contractions are often irregular and spaced well apart; as labor advances, that gap typically narrows and each contraction tends to last longer.

You may have encountered a specific numeric guideline built around this pattern, such as contractions occurring around every 5 minutes, lasting around 1 minute, for at least an hour. Numbers like this are commonly cited general guidelines, not a rule that applies identically to every pregnancy. Exactly when to head to the hospital or call your midwife depends on factors specific to you, including how far you are from the hospital, whether you’ve given birth before, and any specific instructions your provider has already given you. That guidance should come from your own healthcare provider, not from a general number found on a website, and it’s worth confirming your provider’s specific instructions well before labor begins rather than during it.

Braxton Hicks versus labor contractions, in general terms

It’s common to feel practice contractions, often called Braxton Hicks contractions, before actual labor begins, and telling the two apart by feel alone can be genuinely difficult. In general terms, Braxton Hicks contractions are commonly described as irregular in timing and don’t typically intensify or grow closer together over time; they may ease up with a change in position or activity. Labor contractions, by contrast, are typically described as becoming more regular, closer together, and stronger as time goes on, and generally don’t ease up with rest or a change in position.

This is a general, commonly described distinction, not a diagnostic test. If you’re unsure whether what you’re feeling is Braxton Hicks or labor, timing what you’re feeling and contacting your provider is a reasonable next step; they, not a general guide, are positioned to interpret what you’re describing for your specific pregnancy.

What this tool does, and doesn’t do

The Contraction Timer logs start times, durations, and the interval between contractions so you have an accurate record to describe to your provider or bring with you, rather than trying to recall the timing from memory. It doesn’t interpret your results, predict how far along your labor is, or tell you when to go to the hospital. Those determinations belong to you and your healthcare provider.