The best analogue basal body thermometer in the world

geratherm mercury freeThe best analogue basal thermometer worldwide is the Geratherm Mercury Free Classic Thermometer. All the information about measuring and reading it only here!

I’ve recently started this blog together with Marcus in English language and therefore I have gathered information about suitable basal body thermometer in English-speaking countries. An analogue basal body thermometer by Geratherm immediately caught my eye. Until then I had thought that the Geratherm Classic Basal Body Thermometer and the Geratherm Basal are the only suitable analogue thermometers for the Symptothermal Method. But I was wrong. There is also the „Geratherm Mercury Free Oral Glass Thermometer”! I will tell you in this article why I think that this analogue basal body thermometer is currently the best basal thermometer in the world. For this purpose, I will rate the thermometer concerning design, functions and handling and give helpful tips to measure the basal body temperature with analogue thermometers.

Functions of the Analogue Thermometer


Geratherm classic Thermometer inserted into the shaking help

The absolute highlight is probably that this analogue thermometer can take the temperature in °F (degrees Fahrenheit) as well as in °C (degrees Celsius). It therefore has the two most commonly used thermometer scales and can therefore be recommended to every woman in the world, even if she is from the United States. It also comes with a shaking help, with which you can shake the thermometer down more easily after using it. Because of the long scale up to 42°C it can be used as a clinical thermometer as well as basal body thermometer. Compared to the Geratherm Classic which doesn’t come either with the double scale nor with the shaking help, these two features are definitely an improvement and make the Geratherm Mercury Free Oral Glass Thermometer the best analogue thermometer in the world for me. Nevertheless, I still see potential for improvement, if there would be a reading help – i.e. a magnifying glass in the case – which is not absolutely necessary but would make it even more easy to read and to record data.



Well, taking your temperature with analogue thermometers basically is very simple. You just measure for three minutes at a suitable spot (oral, vaginal or rectal). If possible, you have to use the same measurement method during one cycle and keep record of the figures in a suitable cycle chart or a Fertility Awareness app directly after measuring. With digital thermometers it is possible to save the figure. That is not possible with analogue thermometers. You also have to shake down an analogue thermometer after having used it and taken note of the figure in order for a next measurement to be even possible. Now there is finally a shaking help similar to the one for the Geratherm Basal and I have explained exactly in my insider tips how you can use this to shake down the thermometer more easily and with less effort. Of course, you have to be a bit careful when shaking down so you don’t hit anything and break the basal body thermometer. That happened to me more than once already. If I had been more careful here, the thermometer could have lasted for a lifetime. After using it and shaking it down you can conveniently wash and clean the basal body thermometer with lukewarm (!) running water. You have to be careful when cleaning it, because if the water is too hot (more than 42°C), the thermometer can also get broken.


The design is plain, simple and classic with a retro look. As someone with ecological orientation I think it is quite nice, but surely this is a matter of taste. I have thought a long time about why the thermometer has a transparent green case. But then it became clear to me that there can’t be another colour for this analogue basal body thermometer. We associate green with pro nature and environment and that is just what this thermometer is. After all, this basal body thermometer is completely plastic free, at least if you ignore the case. Furthermore, it is mercury-free, antiallergic (nickel-free, PVC-free etc.) and is made for life. The Geratherm Mercury Free Oral Glass Thermometer is really eco-friendly, especially compared to digital thermometers. Digital thermometers contain chemical batteries, are mainly made of plastic and sometimes have to be replaced after a year because the accuracy is no longer adequate when using it for the Sympothermal Method. It is well-known that green is the colour of hope and I think that applies very well with the subject of trying to have baby .


The *Geratherm Mercury Free Oral Glass Thermometer is cheapest in the UK version of the well-known online shop Amazon in my opinion. The price here is around five pounds including shipping, which is about 5.50 € according to the current exchange rate. Unfortunately, you can’t find the thermometer in German online shops or pharmacies! I cannot unfortunately understand the customer reviews; in Great Britain the Fertility Awareness is not very common and the trick with the shaking help apparently has not gotten about until now!

Conclusion and help with the decision to buy

In my opinion, the Geratherm Mercury Free Oral Glass Thermometer is currently the best analogue basal body thermometer in the world and it combines the most important advantages of the Geratherm Basal and the Geratherm Classic. For one thing, this basal body thermometer can further be used as a clinical thermometer even after the wish to have children was fulfilled. And for another thing, it can be shaken down more easily if you know the right technique and use the shaking help. Thirdly, it is eco-friendly and can be used on a life-long basis. Often the curves run more smoothly with an analogue thermometer, making it easier to analyse the temperature curve. The greatest thing is the double scale with Fahrenheit and Celsius. The only thing I would improve is the case, which – shatterproof and with magnifying class – could probably hardly be beaten. And five to six Euro is not a lot for an analogue basal body thermometer with so many advantages.

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