Contraction Timer

What Is the 5-1-1 Rule?

The 5-1-1 rule is a when-to-go-in threshold: contractions 5 minutes apart, lasting 1 minute each, sustained for 1 hour. A contraction timer built on the 5-1-1 rule does not diagnose labour — it compares three measurements (frequency, duration, and how long the pattern has held) against the point where most full-term labours have moved from early labour into active labour. Active labour — begins — when the cervix is dilating steadily, conventionally from about 6 cm in modern guidance (ACOG, 2024; Zhang et al., 2010), and contractions that meet 5-1-1 correlate well with that transition for most people.

Each number in the rule carries a specific job. Frequency of 5 minutes (start-to-start) means the uterus is getting regular recovery windows but little true rest. Duration of 60 seconds means each contraction is long enough to be doing cervical work rather than practice tightening. One full hour means the pattern is a trend, not a coincidence of two or three tightenings. Miss any one of the three and the pattern usually still belongs to early labour, which is why single-number advice ("come in at 5 minutes apart!") misleads so many first-time parents.

If you are still counting down to the big day rather than counting contractions, our Due Date From LMP calculator pins down your dates, and the Week-by-Week Guide walks through what changes in the final weeks before labour begins.

How to Use This Contraction Timer

1. Time three or four contractions in a row. Note when each one starts and when it fully fades. Duration is start-to-finish of a single contraction; frequency is start-to-start between contractions.
2. Enter the typical duration in seconds. Use the most common length, not the longest outlier. Early contractions run 30–45 seconds; active-labour contractions run 60 seconds or more.
3. Enter the start-to-start interval in minutes. If contractions start at 10:00, 10:07 and 10:13, the interval is roughly 6–7 minutes.
4. Count the last 60 minutes honestly, including short contractions, then add your current week of pregnancy and press Calculate. The checker returns your pattern category, your frequency and duration restated plainly, and the action most maternity units would advise.

The insight most timing apps bury: your trend over an hour matters more than any single reading. Contractions that are shortening their interval (10 → 8 → 6 minutes) while lengthening (35 → 50 → 60 seconds) are a labour pattern organising itself, even before it crosses 5-1-1. Retime every 30–60 minutes rather than staring at the clock continuously — labour progresses faster when you rest between checks.

How the Check Works

The checker applies three thresholds in order. First, safety screening: before 37 weeks, regular contractions (four or more in an hour, or a start-to-start interval of 10 minutes or less) trigger a "call now" result regardless of the 5-1-1 maths, because preterm labour is assessed on a different pathway (ACOG, 2024). Second, the full 5-1-1 test: interval at or under 5 minutes, duration at or over 60 seconds, and roughly ten or more contractions in the hour (the count a true 5-minute pattern produces) returns "time to go in." Third, a near-miss band (interval ≤ 7 minutes, duration ≥ 45 seconds, eight or more per hour) returns "get ready," and everything else at term returns an early-labour result with home-care advice.

Worked Example

Imagine contractions at 38 weeks that last 65 seconds, start every 5 minutes, and have done so for the past hour — twelve contractions in 60 minutes. The checker tests the rule in sequence: interval 5 ≤ 5 ✓, duration 65 ≥ 60 ✓, sustained for an hour with a matching hourly count ✓. Result: the pattern meets the 5-1-1 rule, and the advice is to call the maternity unit and head in as advised. Change just one input — say the same 5-minute spacing but contractions of only 30 seconds — and the result drops to early labour, because short contractions at that spacing usually are not yet dilating the cervix steadily. That single-variable sensitivity is exactly why all three numbers are collected instead of asking "how far apart are they?" alone. Our guide on what pregnancy discharge looks like explains the mucus-plug and bloody-show signs that often appear in the same final days, and our post on whether cramping is normal in early pregnancy covers the far more common early-pregnancy end of the cramping spectrum.

Contraction Patterns at a Glance

Treat the table as orientation, not permission to wait. Two data points override every row: your waters breaking and a reduction in your baby's movements. Pair this timer with our Kick Counter in the final weeks — movement pattern plus contraction pattern is the combination triage midwives actually ask about on the phone.

How Accurate Is the 5-1-1 Rule?

The 5-1-1 rule is a well-tested heuristic, not a measurement: it identifies the early-labour-to-active-labour transition correctly for most full-term, first-time labours, but individual variation is wide. Some people dilate quickly with contractions that never quite reach 60 seconds; others sit at textbook 5-1-1 for hours in a long latent phase. Second and later labours typically move faster, which is why many units advise experienced parents to call earlier — at 6–7 minute spacing — rather than waiting for the full rule. The honest accuracy statement is this: if you meet 5-1-1, you almost certainly should be assessed; if you do not meet it, you may still need assessment for the override signs (broken waters, bleeding, reduced movements, pain you cannot cope with, or simply feeling that something is wrong — parental concern is itself a triage criterion, RCOG, 2023).

A caveat competitors rarely mention: contraction timing by hand is systematically optimistic. People tend to start the clock a few seconds after a contraction begins and stop a few seconds before it fully fades, shaving perhaps 10–15% off true duration. If your hand-timed durations hover at 55–60 seconds, treat them as meeting the 60-second leg of the rule and let the overall trend decide. This checker cannot feel intensity, and intensity — contractions you cannot talk through — is the third signal clinicians weigh alongside frequency and duration.

Contractions Before 37 Weeks

Before 37 weeks, the 5-1-1 rule does not apply: any regular contraction pattern deserves a same-day phone call. Preterm labour — defined as regular contractions with cervical change before 37 weeks — affects roughly 1 in 10 births worldwide (WHO, 2023), and early assessment opens options that waiting closes: fetal monitoring, tests for infection, corticosteroids to mature the baby's lungs, and medication to slow contractions where appropriate. Warning companions that raise the urgency include pelvic pressure, a change in vaginal discharge (especially watery or blood-streaked), low backache that comes in waves, and cramps resembling period pain. Our explainer on when ectopic pregnancy pain starts shows the same principle at the other end of pregnancy — pattern plus timing, not pain alone, drives the right decision — and our article on what a chemical pregnancy is covers why very early losses are usually watched rather than treated.