Fertility Tracker – Natural Hormone-Free Ovulation Monitor & Fertility Awareness Device – Smart BBT Thermometer with App for Cycle Tracking, Conception, or Pregnancy Planning – FSA/HSA Eligible
Original price was: $319.00.$239.00Current price is: $239.00.
Price: $319.00 - $239.00
(as of Aug 15, 2025 00:36:05 UTC – Details)
From the brand
Welcome to Daysy – your trusted partner in modern cycle and fertility tracking.
Our mission is to offer you a simple, accurate, and natural approach to family planning and to help you understand your menstrual health.
For over 40 years, we’ve been at the forefront of innovation and precision, empowering women, teens, and menstruating individuals worldwide to make informed, confident decisions about their health and future.
Start your hormone-free life.
Are you trying to conceive? Planning a pregnancy or postponing it? We are always by your side
Your cycle, your body, your well-being.
With cycle tracking, you gain a deep understanding of your body, take control of your fertility, and support your overall well-being, precisely, simply, and efficiently.
Science you can trust. Accuracy you deserve.
Backed by 40 years of research, our advanced menstrual cycle computers offer 99.4% accuracy in distinguishing between fertile and non-fertile days.
Our mission: Your health, your power.
We believe every woman deserves to understand her body. That’s why we create science-backed, intuitive solutions that put your health and autonomy first.
Product Dimensions : 1.81 x 1.89 x 0.87 inches; 1.41 ounces
Batteries : 1 C batteries required. (included)
Date First Available : November 7, 2017
Manufacturer : Valley Electronics AG
ASIN : B01HNCPTWQ
Best Sellers Rank: #195,163 in Health & Household (See Top 100 in Health & Household) #77 in Ovulation Tests
Customer Reviews: 4.4 4.4 out of 5 stars 296 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
Take Control of Your Fertility with Daysy — A hormone-free, precision fertility tracker. Easily predict your fertile and non-fertile days with the help of its free app, empowering you to make informed decisions about your health and family planning.
Know Your Fertility Status in an Instant — Daysy uses a simple red (fertile) or green (not fertile) light to clearly show when you’re most likely to conceive, making it easier than ever to track your cycle.
Crafted in Germany & Designed in Switzerland — Daysy brings over 40 years of research and innovation to your fingertips. Trust a family-run company dedicated to giving you accurate, cutting-edge fertility insights.
Accurate Results You Can Count On — With a stunning 99.4% accuracy, Daysy reliably identifies your fertile and non-fertile days, making it your go-to tool for smart family planning and cycle tracking. Say goodbye to guesswork and hello to certainty.
Forget About Subscriptions! — Daysy’s free app is all you need for tracking your cycle. By combining basal body temperature with advanced algorithms, it provides personalized fertility insights, going far beyond simple period tracking.
Customers say
Customers find the fertility tracker’s functionality positive. However, the ease of use receives mixed feedback, with several customers noting a significant learning curve.
13 reviews for Fertility Tracker – Natural Hormone-Free Ovulation Monitor & Fertility Awareness Device – Smart BBT Thermometer with App for Cycle Tracking, Conception, or Pregnancy Planning – FSA/HSA Eligible
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Original price was: $319.00.$239.00Current price is: $239.00.
Cordelia K. –
Perfect to know your cycle!
Amazing tool!
guerloudy –
DAYSY WORKS!
I honestly DONT know how anyone can have an issue with this device. Those who do either didnât read the Manual so the learning curve must seem steep or miss temperature days which is the whole point of how this device predicts. Iâve only had this device for two months and already it is MIND BLOWING on how accurate it is. I do manual FAM charting to cross reference and to be safe but each time it matches DAYSYâs predictions.Please go on the DAYSY website BEFORE buying to determine if you are compatible with this device. It helps more to have a consistent cycle. READ THE MANUAL!!! It helps to understand the button faster, its colors, and rules on exceptions. Watch YouTube videos on DAYSY reviews and instructions to understand the device.I will say that the app was annoying on the day I set up the DAYSY(syncing issues). So If you are not a very patient person or if you try to do it on the go, I can see how you can assume that itâs not working. But since set up( which took an hour or so) it has run smoothly. I have forgotten to put in my period and gone back the day after to do so. Iâve also put my period on the wrong day accidentally and corrected it very easily. Correct things as soon as possible. Itâs not a magical stick. You need to give a bit of attention and consistency to get the most out of it.
Alissa –
Daysy
Instructions are very clear, have been using for about a year or so now. Plug it in every couple months and youâll be good to go.
Amazon86 –
Inversión que merece la pena
Me costó mucho decidir en comprarme Daysy por su elevado coste.HabÃa leÃdo quejas por la tardanza del dispositivo en darte más dÃas verdes (que son los dÃas seguidos para mantener relaciones sin embarazo). En mi caso que soy irregular y solo llevo un ciclo, ya me ha detectado para este mes 11 dÃas verdes.En Europa es considerado como un dispositivo médico. Tiene una fiabilidad del 99.4%, una pasada, teniendo en cuenta que no hay hormonas que dañen tu cuerpo.A dÃa de hoy, estoy completamente segura de que hice bien en invertir ese dinero. La tranquilidad que te da, el tener tu cuerpo libre de hormonas si no quieres un embarazo, o al contrario, saber cuándo es el momento en que estás ovulando para buscar un embarazo. Incluso es capaz de detectar un embarazo por la temperatura.Claro que tarda aprender el patrón de temperaturas de tu ciclo, ya que cada mujer es distinta. Vivimos en una sociedad en la queremos todo para ayer, y hay cosas que merecen la pena tirar de paciencia, el porcentaje de fiabilidad es altÃsimo, hay que tener en cuenta que los años fértiles de una mujer, es un tiempo prolongado en nuestra vida, y merece la pena unos meses de testeo, a cambio de la fiabilidad que ofrece, tanto si buscas embarazo, como si no.Cada mes que pase te va a ir poniendo más dÃas verdes.Yo solo puedo recomendarlo, lo único que me apena, es no haberlo descubierto hace años…
Shawnee –
Dumb smart device with a huge learning curve
This has to be my biggest Amazon purchase regret and I wish I could return it after 4 months of trying. It is so hard to use, hard to remember how to use, the app sucks, and this technology is not nearly as smart as it leads you to believe. You canât track your period start days unless you remembered to take your temperature that morning and you canât go back and update information from over 3 previous days so if you forgot to take it your temperature youâre screwed. You have to manually sync the Daysy to the app and the app to the Daysy- this is fairly straightforward but not something youâd expect from a $300 device. The app feels outdated and pales in comparison to competing apps like Flo. I sincerely do not know how this has 5 star reviews on every platform. If it were $20, itâs totally worth the money. Maybeeee $100. But $300 is ridiculous for how cheap it feels, how outdated it is, and how complicated it is. I seriously doubt this was even made by women for women.
Carlos Angulo –
Works great, the app makes it more useful than classic competitors
We used the Baby comp for almost 12 years, which was great, but limited. Daysy makes data available to you by using the ios or android app, and there is also an option for making data available for husbands. This device can help you plan your family in a sustainable and healthy way.
Stori Evans –
Learning curve, easy to use, fun, interesting
This a great alternative if you trying to avoid hormonal birth control. I have been using it over a month and learning about how it works before I get married this fall. I am still learning about this device ,but after awhile you get the hang of it. It also has helped me to learn more about my body and the way it works more so than I knew before. The videos for Daysy on the website is very helpful and highly suggest it. Also the people on the website are awesome at answering questions/helping.
annon –
In love with this little thermometer
I loved the idea of the daysy when the first model came out. At the time it was not in my price range . Fast forward 2021 hormonal bc just isnât for me so I decided to try it out . Itâs nice how this is super easy to do and syncs flawlessly to my iPhone . Iâve had zero issues with the syncing . Color coding very easy to understand
Luke –
This has been such a game changer for me and my partner. Iâve been using this for 1 year and I will never go back to Birth Control. I was on the implant for 6 years before finally making the switch. We have had no accidents and I get lots of green days now.When you get the Daysy, it takes time for it to learn your cycle, you must be prepared to be patient. There are reviews on here moaning because theyâve only waited 3 months, it took mine about 8 months before I was consistently getting lots and lots of green days. From months 3-6 I was getting about 5 green days a month (including period). Now Iâm sat at 15 green days a month.Iâve also seen people recommend Natural Cycles as a replacement for this. The Daysy is far superior. My sister in law was on Natural Cycles while I was on Daysy, she just recently welcomed a baby into the family two months ago.Patience is key with this device to reap the rewards. This isnât a âquick fixâ. You are potentially undoing, years of birth control / hormone damage. Your body needs time to sort itself out and you will get a lot of yellow / red days during this time period. Yes itâs frustrating but my god itâs so worth it.
Amazon Customer –
I have just been using for a little while but the instructions are really good and clear and it is super easy
LL –
Daysy lässt sich super einfach bedienen und ist ein fester Teil meiner Morgenroutine. Das Messen geht schnell und ich finde es toll meinen Zyklus so einfach im Blick zu haben. Die App ist sehr übersichtlich und hilfreich. Ich kann Daysy wirklich empfehlen!
Diana fuel –
La verdad lo compre hace más de 8 meses por mi deseo de quedar en embarazo y no habÃa puesto reseña esperando y mirando todas las opciones por si era solo a mi que no me funcionaba, hasta lo envié a Alemania y lo revisaron, dicen que funciona perfectamente pero que soy yo quien no sabe utilizarlo…como si abriendo la boca y meterse un medidor fuece de mucha ciencia, en fin por más que pedà devolución de dinero, no me lo dan porque a ellos si les funciona y claro no pierden…asà que 300⬠tirados a la basura…es más tengo aplicación de calendario menstrual gratuito en mi móvil y funciona mejor, aparte que aunque esté Daysi no me mide la temperatura, si me dice los dÃas en que me va a llegar la regla y los dÃas fértiles y los dÃas que no, entonces para que tenerlo? Si me da la misma información que mi aplicación gratuita en móvil?no es confiable, porque loa información que da no es relevante y no me da seguridad que me ayudara a algo
TaN –
Trovo Daysy fantastica! Ã semplice da usare e insieme al Applicazione si ha la propria temperatura sotto controllo. Consigliatissima!!!