HCG Calculator

Enter either your ovulation date or last period date with length of menstrual cycle. The calculator will take moments to predict your implantation date and complete window.

First β-hCG Level (mlU/ml)

Second β-hCG Level (mlU/ml)

Time Measurements


Created By:

Emily Smith
Emily Smith

Emily Smith

Emily holds a Bachelor's degree in Computer Science from a renowned university. She continued her education with specialized courses in mathematics and data analytics.

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Verified By:



Adam holds a Master's degree in Public Health with a focus on reproductive health and epidemiology.Adam has worked closely with healthcare providers and policymakers to develop evidence-based strategies.

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Based on Research By: Kurt T Barnhart, Symptomatic patients with an early viable intrauterine pregnancy: HCG curves redefined.; Chinedu Nwabuobi, hCG: Biological Functions and Clinical Applications.

Note: The product on this page can provide estimations only due to the change in the length of the menstrual cycle. The results can not replace medical advice by a Doctor.

Wondering how your hCG levels are changing during pregnancy? Simplify tracking with the help of the hCG calculator. By entering a few simple inputs, get the hCG difference, doubling time, and daily increases to have a clear picture of pregnancy progression. 

What Are HCG Levels?

HCG is an acronym for human chorionic gonadotropin. This hormone is formed by cells in the placenta during pregnancy and helps to indicate a pregnancy. After 11 days of conception, it is detectable by a blood test, and about 12-14 days after conception by a urine test.

When the egg gets fertilized, the production of the HCG hormone starts. Its level starts increasing till the 12th week of the pregnancy. This is the peak point and after that, it starts decreasing till the end of the pregnancy period.

It helps the doctors in predicting how far along a pregnant woman is and helps to check how well the pregnancy is going on.

What You Need to Know About Your HCG Levels?

HCG Levels Chart:

During pregnancy, all the weeks have a specific HCG value as shown below:

Gestational age hCG blood levels
Not pregnant - negative Less than 5 mlU/ml
3 weeks 5 to 50 mlU/ml
4 weeks 5 to 426 mlU/ml
5 weeks 18 to 7340 mlU/ml
6 weeks 1080 to 56,500 mlU/ml
7 to 8 weeks 7650 to 229,000 mlU/ml
9 to 12 weeks 25,700 to 288,000 mlU/ml
13 to 16 weeks 13,300 to 254,00 mlU/ml
17 to 24 weeks 4060 to 165,500 mlU/ml
25 to 40 weeks 3640 to 117,000 mlU/ml

Source: parents.com.

Here’s what you need to know:

  • The hCG levels double every 72 hours
  • If the hCG level is less than 5 mIU/mL is considered negative and if it is above 25 mIU/mL, then it is considered positive for the pregnancy test
  • Having an hCG level between 6 and 24 mIU/mL means that you lie in the grey area and you need to rest
  • If the hCG level reaches 2,000 mIU/mL, then it is recommended to perform a diagnosis by the ultrasound
  • Performing multiple hCG pregnancy tests is necessary for the precise assessment of the pregnancy
  • Never use hCG levels to date a pregnancy because they can vary
  • There are two types of hCG tests. A qualitative test detects if hCG or quantitative test (or beta)

HCG Doubling Time: What Does It Mean?

According to Dr. Matthews: 

“During 4 to 6 weeks of the pregnancy, the hCG level should double every 48 hours. If it does not happen, then recheck it after another two days as it can show a failing pregnancy or a PUO (pregnancy of unknown origin)”

The hCG doubling time is crucial, indicating:

  • Early Pregnancy Confirmation: HCG is used to confirm pregnancy and helps in monitoring the progress, especially in the early stages of the pregnancy. Doubling time lets you assess whether the pregnancy is progressing in the expected way or not. typically hCG level gets doubled every 48 to 72 hours when the first few weeks of pregnancy are going on!
  • Viability Indicator: The doubling time assesses the development of the pregnancy
  • Monitoring Ectopic Pregnancy: If the doubling time is slow, then it means there is a chance of ectopic pregnancy (embryo implants outside the uterus) and you must visit a doctor
  • Assessing Risk of Miscarriage: If the doubling time is increasing normally, then it means that everything is fine, but if it's not, then it can raise many risks of miscarriages and other complications during pregnancy
  • Clinical Significance: In the case of complications, the hCG and doubling time are used to monitor the pregnancy

How To Calculate Doubling Time?

To calculate the doubling time, use the following formula:

\(T_2 = \dfrac{T}{Log_2(\dfrac{hCG_2}{hCG_1})}\)


  • T is the representative of the time between measurements (hours);
  • hCG1 is the first hCG measurement
  • hCG2 is the second measurement


Suppose you have two hCG measurements:

  • hCG Level at Time 1 (Earlier Time): 100 mIU/mL
  • hCG Level at Time 2 (Later Time): 300 mIU/mL
  • Time Elapsed between Measurements= 2 days

Now, let's calculate the doubling time using the formula:


Put the given values in the doubling time formula:

\(T_2 = \dfrac{T}{Log_2(\dfrac{hCG_2}{hCG_1})}\)

\(T_2 = \dfrac{2}{Log_2(\dfrac{300}{100})}\)

\(T_2 = \dfrac{2}{Log_2(3)}\)

\(T_2 = \dfrac{2}{1.585}\)

\(T_2 = 1.26\ days\)

Skip the hassle of manual calculations and turn to this hCG calculator. gain clarity on your pregnancy's progress. Determine the doubling times, identify issues early, consult with professionals, and have the best care during pregnancy.

Frequently Asked Questions:

What Does A Low hCG Level Mean?

A low hCG level can indicate various factors. Rechecking within 48-72 hours is crucial to monitor changes. Possible indications include:

  • Ectopic pregnancy
  • Miscalculation of pregnancy dating
  • Possible miscarriage or blighted ovum

Is A High hCG Level A Bad Thing?

A high hCG does not indicate any problem with the pregnancy, if a woman has a high hCG it points towards:

  • Molar pregnancy
  • Miscalculation of pregnancy dating
  • Multiple pregnancies

When Does hCG Stop Doubling?

When the hCG level crosses 6,000 mIU/ml, then it may double in more than 4 days. Meanwhile, you can expect the stopping of hCG rise between the 8th and 11th week of your pregnancy. At this time the hormones reached their peak value. 

What hCG Level Indicates Miscarriage?

In case of a miscarriage, hCG levels start decreasing from previous values. For instance, a baseline level of 120 mIU/mL that dropped to 80 mIU/mL two days later shows that the body is not providing the necessary hormones for the growth of the embryo. 

What hCG Level Indicates Twins?

For singletons, the hCG range is 5 – 397, and for twins, the range is 48 – 683. 

<div class="col s12 padding_b_20" style="overflow: auto;">

- n % Median Range
Viable pregnancies 459 59.1 126 5 683
Singletons 362 47 115 5 397
Twins 96 12 201 48 683
Triplets 1 0.1 317 317
Non-viable pregnancies 315 40.9 31 5 268
Biochemical 154 20 18 5 81
Ectopic 20 3 35 5 144
Miscarriages, all 138 17.6 60 5 268
Miscarriages, late 5 0.6 96 74 116
Hydatidiform mole 2 0.3 99 39 160