hCG calculator: how many weeks pregnant am I?
Enter your blood test result to see which weeks of pregnancy it fits. Add a second result from two days later to check how fast it is rising. Your numbers stay in your browser.
Your result
Compare with my dates (optional)
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Enter a result to see where it falls
The chart shows the typical range for each week on a log scale, because levels climb from single digits to tens of thousands. Your result appears as a line across the weeks it fits.
Typical hCG range by week
Typical range (5th to 95th percentile) Weeks your result fits Week by your dates
Level in mIU/mL, log scale. One laboratory's table, Roche test, weeks counted from the last period.
Enter two results to check the rise
Example: 1,200 on a Monday and 2,500 on the Wednesday is a rise of about 108% over 48 hours, with a doubling time of about 45 hours. Your own numbers replace this as soon as you type them.
What this means
Get urgent help for these signs
hCG numbers can look fine in an ectopic pregnancy, so symptoms matter more than any calculator. The NHS describes the signs of an ectopic pregnancy as usually appearing between weeks 4 and 12.
- One-sided pain low in the belly, shoulder tip pain, or bleeding or brown discharge with a positive test.
- Sudden, sharp pain with dizziness, feeling faint or being sick. Treat this as an emergency.
Call your local emergency number (911 in the US and Canada, 999 in the UK, 112 across the EU, 000 in Australia, 111 in New Zealand) or go to the nearest emergency department. This page does not replace medical care, and our disclaimer explains more.
More pregnancy calculators
See all pregnancy calculatorsHow the calculator works
- 1Match your number to the weeks Result against weekly ranges Your result is compared with the typical range for each week from 3 to 18, counted from the first day of your last period. Every week whose range contains your number is highlighted.
- 2Compare it with your dates Last period to test date Add the first day of your last period and the calculator counts your completed weeks on the day of the test. It then says whether your result sits within, under or over the typical range for that week.
- 3Check the rise (second ÷ first) ^ (48 ÷ hours) − 1 With two results it works out the change over 48 hours and the doubling or halving time. It then sets the change beside the slowest rise seen in ongoing pregnancies and the UK thresholds.
What your result can and cannot tell you
An hCG number is one clue. It is most useful as a pair of results over time, and it needs a scan to be put in context.
What the calculator uses
- Your hCG result in mIU/mL or IU/L, which are the same number.
- If you add them, the first day of your last period and the date of the blood test.
- For the rise check, two results and the hours between the blood draws.
What it cannot tell you
- Date your pregnancy. The ranges overlap, and after about week 8 they overlap a lot.
- Show where the pregnancy is growing. Only an ultrasound can.
- Say whether a pregnancy is healthy or will continue. One result cannot do that, and two results cannot either.
- Replace the range printed on your own lab report. Different tests give different numbers.
- Interpret results after fertility treatment that uses hCG injections. Your clinic sets those ranges.
What hCG is and why it is measured
Human chorionic gonadotropin (hCG) is a hormone made by the cells that go on to form the placenta. It first appears after the embryo implants, and it is the hormone that home pregnancy tests and blood tests look for. A urine test shows whether hCG is above a set level. A quantitative blood test measures how much is there, and it is often called a beta hCG.
Early in a pregnancy that continues, hCG climbs fast. A Canadian laboratory's guide for clinicians says it roughly doubles every two days in the first weeks. The level then peaks at about weeks 8 to 10, and it settles lower for the rest of the pregnancy.
Clinicians ask for serial hCG tests for a few reasons: to confirm an early pregnancy, to follow a pregnancy when there is bleeding or pain, to help find a pregnancy whose location is not yet clear, to follow hCG down after a pregnancy loss or an abortion, and as part of fertility treatment. If you simply want to know when to test, our guide to when to take a pregnancy test covers it.
hCG levels by week
This is the table behind the calculator. The ranges are the 5th to 95th percentile of results from one Canadian laboratory using a Roche test, counted in completed weeks from the first day of the last period. Nine in ten results in that laboratory's pregnant patients fell inside the range for their week.
| Weeks since last period | Typical range (mIU/mL or IU/L) |
|---|---|
| Week 3 | 5.8 to 71.2 |
| Week 4 | 9.5 to 750 |
| Week 5 | 217 to 7,138 |
| Week 6 | 158 to 31,795 |
| Week 7 | 3,697 to 163,563 |
| Week 8 | 32,065 to 149,571 |
| Week 9 | 63,803 to 151,410 |
| Week 10 | 46,509 to 186,977 |
| Week 12 | 27,832 to 210,612 |
| Week 14 | 13,950 to 62,530 |
| Week 15 | 12,039 to 70,971 |
| Week 16 | 9,040 to 56,451 |
| Week 17 | 8,175 to 55,868 |
| Week 18 | 8,099 to 58,176 |
The laboratory does not publish weeks 11 and 13, and it treats results of 5 to 9 as equivocal when a person is not known to be pregnant. It also warns that its values apply to its own test and should not be used to read results from other methods. Other laboratories and websites print different ranges, some far narrower, so use the range on your own lab report when you have one.
A result of 50,000 mIU/mL sits inside the typical range for week 7, week 8, week 10, week 12 and every week from 14 to 18. That overlap is why the calculator lists several weeks and why a scan is the better way to date a pregnancy. Our guide to the 12-week dating scan explains what a scan measures, and the due date calculator turns your dates into a due date.
How fast should hCG rise?
Four sources set the pace that the rise check compares against. They come from different places and use different cut-offs, which is why advice can differ between a US and a UK clinic.
| Source | What it says |
|---|---|
| Laboratory guide for clinicians (Dynacare, Canada) | hCG roughly doubles every two days early in a pregnancy that continues. The same guide expects a fall of 36% to 47% every two days after a miscarriage. |
| US research, 2004 (287 women with pain or bleeding) | The slowest rise in a pregnancy that went on was 53% over two days, and the median rise was 124%. |
| US research, 2016 (285 women) | The slowest rise was 49% if the first result was under 1,500 mIU/mL, 40% from 1,500 to 3,000 and 33% above 3,000. |
| UK guidance (NICE NG126) | A rise of more than 63% over 48 hours suggests a developing pregnancy. A fall of more than 50% suggests the pregnancy is unlikely to continue. Anything in between needs a clinical review within 24 hours. |
The slowest acceptable rise falls as the starting level climbs, from 49% to 33%, because hCG rises more slowly the higher it gets. A rise below these lines is a reason to be seen soon. A rise above them is reassuring and does not prove anything, because the same laboratory guide notes that about 21% of ectopic pregnancies rise like a pregnancy in the uterus and about 8% fall like a miscarriage. That is why clinicians combine serial results with symptoms and a scan.
The calculator scales a gap that is longer or shorter than 48 hours by assuming steady growth, which is a reasonable approximation and not exact. Use two results from the same laboratory, because tests from different laboratories can read differently.
High, low and falling results
Higher than expected. Dates that are a little off, a pregnancy that is further along than you thought and more than one baby all raise hCG. Some rare conditions do too, and a clinician checks for them with a scan. Levels run higher on average in twin pregnancies, yet the ranges overlap, so hCG cannot count the babies.
Lower than expected. Later ovulation or implantation than your dates assume is one simple explanation, and it is why hCG can look low for the calendar and still be perfectly fine. A pregnancy that is not developing, or one growing outside the uterus, are other possibilities. A repeat test shows the direction, and a scan shows the location.
Falling. After a miscarriage, an abortion or treatment for an ectopic pregnancy, hCG falls. The laboratory guide expects a fall of about 36% to 47% every two days after a miscarriage. hCG can stay detectable for weeks, so a home test may stay positive for a while, which can feel cruel. Your care team will say when to test again, and UK guidance suggests a repeat urine test about 14 days after hCG has fallen. If you are wondering about conceiving again, our guide on how soon you can get pregnant after an abortion covers ovulation, contraception and waiting times.
After fertility treatment. Clinics choose their own test day and set their own ranges, so follow your clinic's numbers. An injection that contains hCG can cause a positive test for days afterwards, which is one reason clinics time the test carefully.
Common questions
Short answers about hCG ranges, doubling and what to do next.
What does my hCG level mean in weeks?
Match your number against the typical range for each week. For example, a result of 1,000 mIU/mL fits weeks 5 and 6 in the table on this page. Ranges overlap, so a result often fits more than one week, and the calculator lists them all.
Can hCG tell me exactly how far along I am?
No. Levels vary a lot from one pregnancy to the next, and they level off around weeks 8 to 10, so a single number cannot pin down the week. Your last period and an early ultrasound give a far better estimate.
What is a normal hCG level at 4, 5 and 6 weeks?
In the laboratory table used here, the middle 90% of results run from 9.5 to 750 mIU/mL at 4 weeks, 217 to 7,138 at 5 weeks and 158 to 31,795 at 6 weeks. Other laboratories publish different ranges, so check the range printed on your own report.
How fast should hCG rise?
Early in a pregnancy that continues, hCG roughly doubles every two days. It does not have to double exactly. US research found the slowest rise in ongoing pregnancies was 49% over 48 hours from a low start, and UK guidance uses 63% as the line for a developing pregnancy. The rise slows as the level climbs.
Is a low hCG level a sign of miscarriage?
Not by itself. A low result can mean ovulation or implantation happened later than your dates assume. The pattern over two results, and a scan, tell you much more than one low number. If you are worried, ask your care team for a repeat test.
Can hCG levels show twins?
Levels run higher on average when there is more than one baby, and the ranges overlap heavily with single pregnancies. A high result cannot say how many babies there are. An ultrasound does.
Can hCG be too high?
A result above the typical range has several explanations, including dates that are a little off, a pregnancy that is further along than you thought, more than one baby and some rare conditions. A clinician looks at it together with your dates and a scan.
What if my hCG stops doubling?
The rise slows as hCG climbs and levels off at about weeks 8 to 10, so slower rises are expected later. A slow rise or a plateau earlier than that is a reason to be seen. Contact your care team the same day and mention any pain or bleeding.
What is the difference between mIU/mL and IU/L?
Nothing, numerically. 1,000 mIU/mL is the same as 1,000 IU/L. Some countries print one unit and some print the other, so you can type the number as it appears on your report.
What is beta hCG?
It is the part of the hormone that blood tests measure, which is why a quantitative result is often called a beta hCG. A blood test can detect smaller amounts than a home urine test, so it can show a pregnancy a little earlier. Our guide to when to take a pregnancy test explains the timing.
How long does it take for hCG to return to zero?
It depends on how high the level was and on how the pregnancy ended, and it can take several weeks. UK guidance asks for a repeat urine test about 14 days after hCG has fallen, and your care team will say when to test again. A home test can stay positive for a while, which can be upsetting.
Do medicines change hCG results?
Injections that contain hCG, used in some fertility treatments, can make a test positive when you are not pregnant and can raise results. Your clinic chooses the test day for that reason and sets its own ranges.
Which countries do these ranges come from?
The weekly table is from a Canadian laboratory that uses a widely used Roche test. The rise thresholds come from US research and from UK guidance. Laboratories in other countries publish their own ranges, and the numbers on your report always come first.
Does this calculator save my results?
No. The numbers stay in your browser and are never sent to us. A session store in your own tab remembers them until you close the tab, so you can switch between the two checks.
Keep reading
Testing 7 min read When to take a pregnancy test for accurate results How hCG builds, why morning tests help and when to test again. 
Testing 6 min read Faint line on a pregnancy test: what it means Why lines vary and how to confirm your result. 
Early signs 7 min read Implantation bleeding or period? How to tell Colour, flow and timing, and the warning signs that need a call to your provider. Sources: Dynacare: Interpretation of serum hCG results in pregnancy (laboratory guide, 2017); Barnhart et al., 2016: Differences in serum hCG rise in early pregnancy by race and value at presentation; Barnhart et al., 2004: Symptomatic patients with an early viable intrauterine pregnancy, hCG curves redefined; NICE NG126: Ectopic pregnancy and miscarriage, diagnosis and initial management; NHS: Ectopic pregnancy symptoms; NHS: Doing a pregnancy test