Medically reviewed by Sophia Yen, MD, MPH – Written by Pandia Health Editorial Team. Updated on January 25th, 2021

Math and birth control… an unlikely but essential combination. There is comfort in understanding the numbers, and it is always recommended that you know how your medication works, including when your sexual health is involved. Let’s take a closer look at the effectiveness of your birth control.

If you want to get started today on preventing unplanned pregnancy with the pill, patch, or ring, sign up with Pandia Health today!

How do I calculate how effective my birth control is?

Have you ever wondered how you can use birth control to decrease your chances of getting pregnant? Many numbers are floating around the internet about the effectiveness of different types of birth control, but Pandia Health is here to simplify this. Let’s look at how you can calculate the effectiveness of your birth control and your chances of getting pregnant when using each method.


Effectiveness of family planning methods


Chances of getting pregnant while on birth control

Implant: Of the people with uteri that use the implant, 5/10,000 usually get pregnant. This gives you a 0.05% chance of getting pregnant if you choose this method. On its own, the implant is the most effective birth control option!

Hormonal IUD: When using the IUD with hormones, 2/1000 women will get pregnant. That means you have a 0.2% chance of getting pregnant using this method.

Copper IUD: When using the copper IUD, 8/1000 women will get pregnant, which means women using this method have a 0.8% of getting pregnant.

Birth control shot: Of the women that use the birth control shot, 6/100 will get pregnant. If you use the birth control shot, you have a 6% chance of getting pregnant.

Birth control ring: How effective is NuvaRing? 9/100 women (9%) will get pregnant when using the birth control ring.

Birth control patch: 9/100 women will get pregnant (9%) when using the birth control patch. This method has the same effectiveness (with typical use) as the birth control ring.

Combined birth control pill: When using the birth control pill, 9/100 women usually get pregnant (9%).

Progestin-only birth control pill (POPs): When using Progestin Only Pills (POPs), 9/100, or 9%, of women usually get pregnant.

Condoms: Using condoms, 18/100 women (18%) usually get pregnant. This method of contraception is the only way to prevent sexually transmitted diseases. To prevent STIs, condoms should be used in combination with another method, like the birth control patch.

Spermicide: When using spermicide alone, about 28/100, or 28%, of women will get pregnant.

*These numbers are for perfect use as directed. The math changes when not used perfectly.

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Birth control effectiveness math


pink calculator



Being concerned about the risk of pregnancy and childbirth is very real. But by combining multiple forms of birth control, the math is in your favor. If you are really worried about pregnancy, Pandia Health recommends these effective combinations that lead to the lowest chances of conceiving when used together.

  • the implant + condoms = 9/100,000 chance of conceiving or
  • IUD with hormone + condoms = 3.6/10,000 chance of conceiving

Here is the math for some other common birth control combinations:

How effective is the pull out method

Without any protection, you will very likely get pregnant. The chance of you getting pregnant without using any form of protection (e.g. birth control pills or condoms) is 85%. Keep in mind, if you don’t use a condom, you also risk catching sexually transmitted infections like HIV.

How can Pandia Health help? 

Want to know what the best method of birth control is for you? At Pandia Health, we take pride in prescribing birth control based on the “Pandia Health algorithm”, which considers several factors, including age, race/ethnicity, BMI, and your personal medical history.

Our expert doctors can advise on the proper use of your birth control, as this can change its effectiveness. For example, taking the pill at the same time every day lowers your risk of getting pregnant. 

With just one $30 payment a year, you can get access to our expert doctors (available in these states) for 364 days. To get started today on preventing unplanned pregnancy with the pill, patch, ring, contact us today!


The above information is for general informational purposes only and is NOT a substitute for professional medical advice. Always seek the advice of your doctor/primary care provider before starting or changing treatment.