The short answer. Time a contraction from the moment the tightening begins to the moment it fully releases — that is the duration. Measure the interval from the start of one contraction to the start of the next. The widely used threshold for going to hospital with a first, full-term baby is the 5-1-1 rule: contractions about five minutes apart, each lasting about a minute, sustained for one hour. Call sooner, without waiting for a pattern, if your waters break, you bleed, movements reduce, or contractions start before 37 weeks.
How to time a contraction properly
A contraction is a wave: the uterus tightens, peaks, and releases. You start the clock at the very first tightening — not when it starts to hurt, which is several seconds later — and you stop it when the muscle fully lets go. That gap is the duration, and in established labour it usually sits somewhere around 45 to 70 seconds.
The interval is where almost everyone goes wrong. It is measured from the start of one contraction to the start of the next — not from the end of one to the beginning of the next. The difference is exactly one contraction's length, which is roughly a minute, and a minute is the difference between "every six minutes" and "every five". Timing from the end makes labour look less advanced than it is. The timer above does it the right way for you; the number in the log is always start-to-start.
One more thing worth knowing before you start: a single contraction tells you nothing. What a doctor wants is the pattern over an hour — are they getting longer, stronger and closer together, or are they wandering? That is a question only a log can answer, which is the entire reason to time them rather than trust your sense of how long the last one felt.
The 5-1-1 rule
The rule most maternity units teach is easy to remember because the numbers are the name:
5 — five minutes apart
Start-to-start intervals of about five minutes. Not one gap of five minutes: consistently around five.
1 — one minute long
Each contraction lasting roughly sixty seconds from first tightening to full release.
1 — for one hour
The pattern sustained for a full hour. This is the part people skip, and it is the part that separates real labour from an energetic evening of Braxton-Hicks.
Some hospitals use 4-1-1 or 3-1-1 instead, and many will tell a second-time mother to come in earlier because second labours often move faster. If your own doctor or midwife gave you a different threshold, theirs wins — they know your history, your distance from the unit and how your first birth went. The timer above uses 5-1-1 because it is the most common starting point, not because it is the only correct one.
Real contractions or Braxton-Hicks?
| Braxton-Hicks | Labour contractions | |
|---|---|---|
| Rhythm | Irregular, unpredictable | Regular, and the gaps shorten |
| Intensity | Stays the same or fades | Builds steadily, hour on hour |
| Where | Usually the front of the bump | Often lower back, wrapping to the front |
| Movement | Often ease if you change position, walk, rest or drink water | Keep coming whatever you do |
| Duration | Vary — 20 seconds to 2 minutes | Settle into a consistent length |
The honest summary: an hour with this timer will usually answer the question when your own judgement cannot. If the intervals in the log are wandering between four and eleven minutes with no direction, that is very likely practice. If they are marching from nine to seven to five, that is not.
For the full picture — mucus plug, waters breaking, the bloody show, and what early labour actually feels like — read the signs of labour guide.
Call now, whatever the timer says
Contact your maternity unit immediately — do not wait for an hour of timing — if:
- Your waters break, and especially if the fluid is green, brown or bloody rather than clear
- You have any vaginal bleeding
- Your baby's movements have reduced or changed — always same-day, never wait-and-see
- Contractions start before 37 weeks
- The pain is constant rather than coming in waves, or your bump feels hard and tender between contractions
- You have a severe headache, vision changes, or pain under your ribs — these can be signs of pre-eclampsia
- You have a fever, or feel generally unwell
- You were told to come in early — group B strep positive, a previous caesarean, a fast first labour, or a long journey to the hospital
What to say when you call
Read the numbers straight off the log. A maternity triage nurse is trying to build a picture in thirty seconds, and these five things give it to them:
- How many weeks you are — from your due date
- How far apart the contractions are, start to start
- How long each one lasts
- How long the pattern has held
- Whether your waters have broken, whether there is any bleeding, and whether the baby is moving as usual
Having the log open while you talk is worth more than trying to remember. It is also why the app version keeps the history — a screenshot of an hour of contractions is a better handover than "they've been coming quite often".
Breathing through them
Timing and coping are two different jobs, and the second one is easier if you have practised. Slow deep breathing is the wrong tool mid-contraction — what works is light, rhythmic breathing through the peak, then one long recovery breath in the gap. The breathing exercises page has two guided timers you can practise with now, and the app's labour-breathing technique unlocks from week 28.
If you have not packed yet, the hospital bag checklist takes about twenty minutes, and this is the moment it stops being theoretical.
What this timer can't do
- Tell you that you are in labour. Only an examination can. It tells you what your contractions are doing.
- Know your history. A second baby, a previous caesarean, a fast first birth or an hour's drive to the hospital all change when you should leave — and the rule does not know any of that.
- Survive a refresh. Nothing is stored. Close the tab and the log is gone.
- Wake you up. There is no sound and no notification, because a browser tab cannot reliably make either happen with the screen off. The app can.
Inside Baby Novum: the same timer with a saved history, rolling averages, and a visual and audible 5-1-1 alert that fires whether or not you are looking at the screen — alongside the breathing techniques, kick counter and birth plan builder.
Related guides
FAQ — Timing contractions
How do you time contractions?
Start the clock when the tightening begins and stop it when it fully releases — that is the duration. The interval is measured from the start of one contraction to the start of the next, not from the end of one to the beginning of the next. Timing them from the end is the most common mistake and makes contractions look further apart than they are.
What is the 5-1-1 rule?
A common guideline for when to go to hospital in a first, full-term, low-risk pregnancy: contractions about 5 minutes apart, each lasting about 1 minute, sustained for 1 hour. Some hospitals use 4-1-1 or 3-1-1, and second babies often arrive faster than the rule assumes — so use the number your own doctor gave you if it differs.
How do I know if these are real contractions or Braxton-Hicks?
Braxton-Hicks are irregular, do not get closer together, are usually felt across the front of the bump, and often ease if you change position, empty your bladder or drink water. Real labour contractions get longer, stronger and closer together, keep coming whatever you do, and are often felt in the lower back wrapping round to the front. An hour on this timer usually answers the question by itself.
Should I go to the hospital when the timer alerts?
The 5-1-1 alert means your pattern matches a common threshold — it is a prompt to call your doctor or maternity unit, who will decide with you. It is not a diagnosis and it does not know your history, your distance from the hospital, or whether this is your first baby.
When should I call before the timer says anything?
Call straight away, regardless of the pattern, if: your waters break (especially if the fluid is green, brown or bloody), you have any vaginal bleeding, you notice reduced fetal movements, contractions start before 37 weeks, the pain is constant rather than coming in waves, or you have a severe headache, vision changes or pain under your ribs. None of these wait for an hour of timing.
Does this timer save my contractions?
No — deliberately. Everything stays in the browser tab and is gone when you close or refresh it, so nothing is stored on a shared phone and nothing is sent anywhere. If you want the log to survive a locked screen, an audible alert, and a history you can show at the hospital, that is what the Baby Novum app is for.
How long should contractions last in active labour?
In established labour, contractions typically last around 45 to 70 seconds and come every three to five minutes. Early labour contractions are shorter and further apart — often 30 to 45 seconds, ten or more minutes apart — and can go on for many hours. Both are normal; what matters is the direction of travel.
The contraction timer — at a glance
Time each contraction from the first tightening to the full release, and measure the gap from the start of one to the start of the next — timing from the end is the mistake that makes labour look further away than it is. The threshold most maternity units teach for a first, full-term, low-risk pregnancy is the 5-1-1 rule: contractions roughly five minutes apart, each about a minute long, sustained for a full hour. Some units use 4-1-1 or 3-1-1, and second labours often move faster, so follow the number your own doctor gave you. An hour of logged contractions is also the cleanest way to separate real labour from Braxton-Hicks: practice contractions wander and fade, real ones get longer, stronger and closer together. None of that applies if something else is happening — waters breaking, bleeding, reduced movements, or contractions before 37 weeks all mean calling now rather than timing for another hour. And when you do call, read the numbers off the log: how many weeks, how far apart, how long, for how long, and whether the baby is moving.
Baby Novum is an informational and tracking tool, not a medical device, and does not provide medical diagnosis or treatment. Always consult your doctor or midwife about your pregnancy.