Irregular Period Due Date Calculator


While embarking on the journey to motherhood, it’s only natural to be curious about your due date- a significant crossroad in pregnancy. You might be, but if you’ve had irregular periods in the past, determining your due date might seem like a challenging task for you. However, do not be bothered. The irregular period due date calculator is a tool that can handle that. Are you skeptical if that’s possible? Let’s explore everything you need to know in this article. 

What is the Irregular Period Due Date Calculator?

The irregular period due date calculator is a specialized tool designed to provide expectant mothers with irregular menstrual cycles an accurate estimation of their due date. Unlike the traditional due date calculations that assume a 28-day menstrual cycle, the irregular period due date calculator takes into account the irregularities in each woman’s cycle to provide a reliable due date prediction. By using your specific cycle length, the calculator presents your result. 

The formula employed by the calculator to achieve this is Parikh’s formula. Check that out in the next section. 

What Formula Does the Irregular Period Due Date Calculator Use? 

The irregular period due date calculator employs a specialized formula called Parikh’s formula to estimate the due date for expectant mothers with irregular menstrual cycles. Developed by Rakesh Parikh an Indian doctor, this formula accommodates the variations in cycle length and timing that occur with irregular periods. 

By using your own specified cycle length in deciding your due date, the formula helps you to arrive at a more accurate estimation of the due date. Here’s what the formula considers: 

1. Menstrual cycle length

The Parikh formula considers the length of your menstrual cycle. Since there are some cycle lengths that are shorter than the average or longer, this formula puts that into consideration. 

2. Add 9 months

The formula requires you to add nine months to the starting date of your last menstrual cycle. 

3. Count 21 days backward

Subtract 21 days from the results you’ve previously gotten. 

4. Add the length of your previous cycle

The last step in the formula is to add the length of your cycle. 

Here’s how the formula looks like

Due date= LMP + 9 months – 21 days + length of cycle. 

Some Example Calculations

  1. Let’s say the LMP is April 1st, 2023 and your cycle length is 23. 

Calculation: 

  • Add 9 months to LMP= April 1st + 9 months = January 1st, 2024. 
  • Subtract 21 days= January 1st – 21 days = December 10
  • Add the length of your cycle: December 10 + 23 days = 3rd of January. 

In this example, the estimated due date is the 3rd of January, 2024. 

  1. Suppose the LMP is September 23, 2022, and the length of the cycle is 30. 

Calculation: 

  • Add 9 months to LMP = September 23 + 9 months = June 23, 2023
  • Subtract 21 days= June 23 – 21 days = June 2
  • Add the length of your cycle = June 2 + 30 days = July 2. 

According to the workings, and the use of Parikh’s formula, the estimated due date is July 2, 2023. 

We understand that manual calculations to estimate your due date might be stressful and tiring. That’s why with the use of the calculator, the process becomes much more manageable. Also, be sure to get reliable results as soon as you are done inputting. Let’s see how the calculator presents your results within seconds. 

How Does the Calculator Calculate EDD from LMP for Irregular Periods?

As we’ve said, the calculator utilizes Parikh’s formula to calculate your EDD (estimated due date)  from your LMP (last menstrual period) for women with irregular periods. Let’s take a close look at how the calculator utilizes Parikh’s formula as an algorithm. 

Step-by-Step Process of the Irregular Period Due Date Calculator:

Enter Last Menstrual Period (LMP) Date: 

You begin by entering the date of your last menstrual period into the calculator. This serves as the starting point for the estimation. When you input, make sure it’s in the month-day-year sequence. 

Enter the Duration of your Previous Cycle:  

Use the – and + bars to select accurately the length of your cycle. You can as well input it manually by clicking in the field provided. 

Estimated Due Date (EDD):

The calculator goes ahead to process your inputs and presents the likely date your baby is to arrive. 

And that’s it! The calculator uses your input to give you an accurate result. That makes it easy for you to be with your due date within seconds. 

How do I know my Due Date if my Periods are Irregular?

Through the Parikh’s formula, it’s evident that you can know your due date if you have irregular periods. This makes it one of the approaches you can use to discover your due date. 

As we’ve earlier discussed, the formula takes into account your LMP and the length of your previous menstrual cycle to figure out your due date. By following the steps of the Parikh’s formula above, you can arrive at a more accurate prediction of when your baby is expected to arrive. 

Alternatively, you can opt for a hassle-free and precise solution by making use of the irregular period due date calculator. This specialized tool which also employs the Parikh’s formula as its algorithm, is built explicitly for expectant mothers with irregular menstrual cycles. By entering your LMP and your cycle’s length, you can get your results within seconds. This tool ensures that you get your due date with ease and confidence, regardless of the irregularities in your menstrual cycles. So, why not go ahead and make use of this tool presented above. 

The Calculator Puts Your Mind at Rest

Having irregular periods before your pregnancy should not add unnecessary stress to your pregnancy journey. Thanks to the irregular period due date calculator, you can totally figure out your due date without the need to worry about uncertainties. 

We’re glad this calculator can put you at rest. However, it’s important to consult your healthcare provider more on your pregnancy and due date as babies can arrive a bit early or even past their estimated due date.