How to time contractions: what to measure and when to call

Your belly tightens, holds and lets go. A few minutes later it happens again, and you start to wonder whether labor has begun. Timing your contractions gives you a pattern you can describe to your midwife or doctor, and you only need a clock to do it.

You measure two things. Duration is how long one contraction lasts. Frequency is how far apart contractions are, counted from the start of one to the start of the next. Over time, those two numbers show whether labor is building.

What you’re measuring: duration and frequency

Duration runs from the moment you feel a contraction begin until your belly softens again. Frequency runs from the start of one contraction to the start of the next. Cleveland Clinic and OHSU both describe it this way, and Cleveland Clinic suggests counting in seconds because that’s easiest.

For example, a contraction starts at 2:10 and ends at 2:11. The next one starts at 2:16. That contraction lasted 1 minute, and your contractions are 6 minutes apart. The 5 minutes in between are your rest.

A common slip is to time from the end of one contraction to the start of the next. That captures only the rest, so contractions look closer together than they really are. In the example above you’d write down 5 minutes instead of 6.

When to start timing contractions

You don’t have to time every tightening. Braxton Hicks contractions can happen for weeks before labor begins; they usually have no pattern and don’t get closer together (ACOG). In early labor, contractions often come irregularly or start and stop, and Kaiser Permanente suggests passing the time with music, a walk or a warm shower, and resting or sleeping if it’s night. If you’re not sure whether you’re feeling practice contractions, the article on Braxton Hicks contractions explains the differences.

Start timing when contractions feel more regular, start to get stronger or seem to follow a pattern (healthdirect). OHSU suggests starting after a few contractions in a row. Boston Medical Center’s rule of thumb is to start once they’re strong enough that you can’t talk or laugh through them.

Under 37 weeks, OHSU asks you to contact your provider immediately at the first signs of labor. healthdirect says to call your birth unit or midwife straight away if you have contractions before 37 weeks.

How to time contractions, step by step

1. When a contraction starts, write down the time or tap your timer.
2. When it fades and your belly softens, note the time again.
3. When the next one starts, note that time too. The gap between the two start times is your interval.
4. Keep going for several contractions and watch how the interval and the duration change over the last hour.
5. Jot down how strong each one felt and whether contractions keep coming when you rest, drink water or move around.

March of Dimes recommends keeping a record of each interval and how strong each contraction feels. It also suggests noticing whether they continue when you rest, drink water or move around. That last check matters because false labor contractions may stop when you walk, rest or change position (ACOG). True labor contractions continue either way.

After three contractions, your notes might look like this:

Start time	Duration	Minutes since last start	Strength
2:10	60 seconds	first one	moderate
2:16	55 seconds	6	moderate
2:21	65 seconds	5	strong

Cleveland Clinic says it helps to write down the start time and length of each contraction. Your notes make it easier to describe your pattern to your provider. healthdirect adds that your midwife or doctor may ask how long contractions last, how strong they feel and how often they come. If your water breaks, note the time, the color and the amount of fluid as well (healthdirect).

You don’t have to do the timing yourself. healthdirect points out that the person supporting you can time your contractions. That leaves you free to breathe through each one.

Timing contractions: app, online timer or pen and paper

Any of these works. Cleveland Clinic mentions a phone app or pen and paper, and healthdirect lists a watch, a clock or a contraction timer app. The difference is how much math you have to do in the middle of a contraction. If you prefer paper, our contraction chart has a log to print, with the typical values for each stage of labor.

	Pen and paper	Online timer	Our app
How you record	Write down start and end times	Tap at the start and the end	Tap at the start and the end, or only at the start
What you see	Whatever you work out yourself	Duration and interval	Duration, interval and the average of the last hour
Rule check	None	Shows how close you are to 5-1-1	Alert at 5-1-1, 4-1-1 or your own rule, with a button to call the labor ward
Where your data stays	On the paper	In your browser	On your phone, no account needed

You can try the online contraction timer right now on this site. It uses the same rule logic as the app, and how the app calculates explains that logic. For labor itself, use the free Contraction Timer app. It works offline and keeps every contraction on your phone. Set it up in the last weeks of pregnancy, with your hospital’s rule and the labor ward’s number. A good moment is when you pack your hospital bag.

What your numbers mean

As labor moves through its stages, contractions get closer together and stronger. ACOG describes true labor contractions as coming at regular intervals and getting closer over time. Each lasts about 60 to 90 seconds. In early labor they’re usually shorter, around 30 to 45 seconds, and may come irregularly (Kaiser Permanente). In active labor, Cleveland Clinic describes contractions lasting 40 to 70 seconds and coming every 3 to 5 minutes. Our guide on how long contractions last has the values for each stage.

Contractions 5 minutes apart and other intervals explains what a single interval means, from 10 minutes down to 3. One number on its own tells you little. The first-baby guidelines below all ask for a pattern that has held for about an hour.

When to call your provider or go to the hospital

Hospitals don’t all use the same numbers. For a first baby, three US health systems give these thresholds:

• OHSU (5-1-1): contractions 5 minutes apart for 1 hour, each lasting about 1 minute.
• Boston Medical Center (4-1-1): a contraction at least every 4 minutes, about a minute long, for at least an hour.
• Kaiser Permanente: contractions every 3 to 5 minutes over an hour, too painful to talk or walk through.

If you’ve given birth before, they advise coming in earlier. OHSU says 5 to 10 minutes apart for an hour. Kaiser Permanente says every 5 to 7 minutes, Boston Medical Center 5 to 6 minutes apart. In the UK, the NHS says to call your midwife once regular contractions come every 5 minutes or more often.

Ask your own hospital which rule applies to you, ideally at a prenatal visit. The 5-1-1 rule article explains that guideline in detail, and when to go to the hospital covers the decision itself.