Home-based ovulation calculator kits

Once a woman ovulates each month, she has only a very short 12-36 hour time-opportunity window to conceive. Many couples therefore use ovulation calculator kits to predict this exact time of ovulation.

The idea behind ovulation calculator kits is that by knowing when ovulation is due it’s possible to time intercourse to coincide with ovulation. This will improve fertilisation chances.

How do ovulation calculators work?

The tests work by measuring the level of luteinizing hormone (LH). Characteristically, LH strongly spikes approximately 36 hours before a woman starts ovulating. This spike is referred to as the “LH-Surge”.

The method for testing LH will depend on the type of urine-based testing kit. In some cases urine will be collected in a cup for testing, or a stick will be held in the urine stream.

A test card or stick will display coloured bands if a LH surge is present. The process is similar to pregnancy tests that are used to detect human chorionic gonadotropin (hCG).

Tips and tricks

Depending on the kit used the instructions will vary slightly. Generally urine should be collected/tested between 10am and 8pm. Most kits instructions recommend testing between 2pm and 2:30pm.

It’s also a good idea to try and test at the same time each day and to reduce liquid intake for approximately 2 hours prior to testing. Urine can be diluted with too much liquid consumption making it difficult to identify a LH surge. Most tests should be read within ten minutes of urine exposure.

Comparing ovulation calculator kits

In a constant effort to find your most fertile window, you will likely be taking many ovulation tests over the course of your pregnancy journey. We therefore think the winning test should offer value for money and convenience.

The SME Fertility strips certainly beats every other the other brands on value. However, if you are not price sensitive and tech-savvy, the advanced monitor it is a good option to collect extra information and make the overall result more reliable.

In general, we believe that a combined monitoring of body temperature, cervical mucus, LH surge and a healthy amount of your own physical awareness is the most effective method for determining your fertility window.


Ovulation Predictor Kits

  • Where to buy
  • Use with Testing Cup
  • Hold in Urine Stream
  • # of test days
  • Hormone(s) tracked
  • Accuracy
  • Notes

SME Fertility

£2.9520 strips
£2.9520 strips

Clearblue Digital

£14.9910 strips
£14.9910 strips
  • 10, 20, 30 packs
  • LH
  • 99%
  • Easy to read digital display. Results ready in 3min

Ovulation Test

£9.997 strips
£9.997 strips

BabyStart FertilTime

£4.595 strips
£4.595 strips

True Ultra Sensitive

£7.9930 strips
£7.9930 strips
  • 30
  • LH
  • 99.5%
  • Wide-tip design. Results ready in 3-5min.

ClearBlue Monitor

  • 10 (additional strips can be purchased)
  • LH and Estrogen
  • 99% for LH surge and pregnancy
  • Tracks and stores fertility and pregnancy information for 6 months.

Advantages of ovulation calculator kits

  • When used correctly, most ovulation calculator kits can be more accurate and easier to use compared with other methods for determining fertile days. Quality kits are around 97% effective in identifying a surge in LH.
  • Ovulation calculator kits can be very convenient and only need to be used during the middle of a cycle. Other methods require a daily commitment, such as charting basal body temperature (BBT).
  • These kits are easily accessible and can be purchased at pharmacies, major supermarkets, some convenience stores and many websites such as amazon.
  • Just like home-pregnancy testing kits, ovulation calculator kits are very straightforward to use. Most kits have multiple testing strips for added convenience.

Disadvantages of ovulation calculator kits

  • Ovulation calculator kits can be expensive, costing between £50 and £100 for high-end brands. A new kit is used each cycle.
  • For women over the age of 40 ovulation calculator kits are not necessarily reliable. This is because as women approach menopause hormone levels naturally fluctuate and often LH levels increase. This can cause a false positive reading not necessarily linked to pending ovulation.
  • Certain medications can interfere with ovulation prediction kit results. Women taking fertility drugs or other medications that affect hormone levels will influence test results making them unreliable.
  • Ovulation calculator kits don’t confirm ovulation; they only predict a surge in LH that usually precedes ovulation. In some cases, the egg fails to be released following a LH surge (luteinized unruptured follicle syndrome).
  • Cervical mucus conditions are unable to be determined by ovulation calculator kits. Cervical mucus must be receptive to sperm to create a fertile environment.

How to get the most value from ovulation calculator kits

Ovulation calculator kits can be very useful in forecasting the surge of LH and subsequent ovulation.

However for the most accurate prediction, these kits should be used in conjunction with charting basal body temperature and regularly examining cervical mucus characteristics.

Leave Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

clear formSubmit

This site uses Akismet to reduce spam. Learn how your comment data is processed.