Last updated: August 5, 2021

Welcome to our big bath thermometer test 2021. Here we present all the bath thermometers that we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the internet.

We would like to make your purchase decision easier and help you find the best bath thermometer for you.

You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy a bath thermometer.


  • There are two types of bath thermometers: analogue and digital.
  • In general, digital bath thermometers can show you the water temperature more accurately.
  • There are many different models and designs. A distinction is made between bath thermometers for babies and for adults.

The Best Bath Thermometer: Our Choices

Guide: Questions you should ask yourself before buying a bath thermometer

What is a bath thermometer?

A thermometer is a measuring device for determining temperature. A bath thermometer measures the water temperature while bathing. Each thermometer we present here consists of a temperature sensor and a display of the measured temperature.

For a relaxing feel-good bath, many people use a bath thermometer to check the water temperature. (Image source: Rice)

Especially for babies, the water temperature is important when bathing. But also when you use bath additives or even perform medical treatments, the temperature of the water is crucial. The right temperature ensures well-being and prevents burns from water that is too hot.

What types of bath thermometers are there?

You can choose between two types of bath thermometers:

  • Analogue bath thermometers
  • Digital bath thermometers

Analogue bath thermometers usually work by measuring the expansion of a liquid in the measuring tube. A scale is attached to this measuring tube, from which you can read how high the water temperature is.

Digital bath thermometers are usually battery-operated, but rarely they also work on solar energy. Digital thermometers have a display that shows the exact water temperature. The temperature is measured either by the expansion of a liquid or by electrical impulses.

How much does a bath thermometer cost?

The price of bath thermometers depends largely on the type of thermometer. In most cases, analogue bath thermometers are cheaper than digital bath thermometers.

Digital bath thermometers are usually more accurate and more complex to produce, which is why they are more expensive than analogue bath thermometers. In addition, digital bath thermometers often offer additional functions, such as measuring the air temperature in the room.

Type Price
Analogue bath thermometer 2-8 euros
Digital bath thermometer 10-20 euros

There are price differences depending on the manufacturer. A big difference is noticeable when you look specifically for bath thermometers for babies. Since they have to be suitable for children and very safe, they are often a little more expensive than bath thermometers for adults.

How do I use a bath thermometer correctly?

Basically, all bath thermometers are waterproof, so you don't have to worry about possible water damage. A few digital bath thermometers have a measuring sensor that is not inserted in the device. Please read the instructions for use before using it.

The optimal water temperature is between 36 and 41 degrees Celsius, so it is best to take care of your well-being.

You should use the bath thermometer to check the water temperature before you take a bath. For this purpose, the bath thermometer can be hung in the bathtub or placed in the water. You should make sure that analogue bath thermometers have enough time to react to the water temperature. Therefore, it is recommended to leave them in the water for at least 2 to 3 minutes until the temperature is reliably indicated.

Very often bath thermometers are used with babies, here you should not rely on the thermometer alone, but also on your feeling and the well-being of your baby. The recommended bath temperature for babies is 37 to 38 degrees.

What alternatives are there to a bath thermometer?

As an alternative to a bath thermometer, you can of course also rely on your feeling. However, if you are diabetic, this is not recommended as the temperature reading is often less accurate. A bath thermometer is also recommended if you are bathing a toddler or baby.

However, if this is not for you, there is an adapter for your tap to regulate the water temperature. These are permanently installed and provide the temperature that you have set.

Decision: What types of bath thermometers are there and which is the right one for you?

What distinguishes an analogue bath thermometer and what are its advantages and disadvantages?

Analogue bath thermometers have proven themselves before digital bath thermometers. They are easy to use and the scale should be easy to read. Before you buy, make sure you know what liquid is used in the thermometer to measure the temperature.

  • Less prone to error
  • Easy to use
  • Usually cheaper than digital bath thermometers
  • Less accurate than digital bath thermometers
  • Depending on the liquid, may pose a health risk if the thermometer breaks
  • Fewer extra functions (such as air temperature measurement)

Analogue bath thermometers are therefore usually limited to their basic functions, but they are also cheaper and can last longer than digital bath thermometers if they are well looked after. Determining the exact water temperature is rather difficult with analogue bath thermometers, but they are easy to use.

What distinguishes a digital bath thermometer and what are its advantages and disadvantages?

Digital bath thermometers are usually a little more expensive to buy. On the other hand, they convince with extra functions and a digital display of the temperature.

  • More accurate than analogue bath thermometers
  • Can measure air temperature
  • Are less harmful to health
  • Reliable technical precision
  • More error-prone
  • Usually more expensive than analogue bath thermometers

The digital display can even show the temperature down to tenths of a degree. If a bath thermometer should break, there are usually no dangerous measuring liquids built in.

The electronics are specially shielded so that there is no danger if your bath thermometer should break. Nevertheless, some customers prefer analogue thermometers, because with digital versions you always have to rely on the technology.

Buying criteria: You can use these factors to compare and evaluate bath thermometers

Before you buy a bath thermometer, you should consider the following aspects:

  • Material
  • Liquid
  • Design
  • Accuracy


Both analogue and digital bath thermometers can be made of a variety of materials.

Analogue bath thermometers are often made of plastic or wood. The measurement is usually taken in a glass or plastic tube with the respective measuring liquid.

Digital bath thermometers naturally also have electronics built in. These include a variety of metals as well as a measuring tube and a liquid.

So the visible materials are particularly different. Often this is also a question of design: perhaps you would rather have a wooden bath thermometer or a plastic bath thermometer in your bathtub.


Besides the traditional mercury thermometers, there are also thermometers with sunflower oil or alcohol.

The temperature is measured by the expansion of the liquid in the presence of heat. Only a few liquids are therefore suitable for use in a thermometer.

Nowadays, you should make sure that there is no mercury in your bath thermometer. The alternatives that have been developed work very well and are not harmful to health.


The design of bath thermometers is varied, from brightly coloured to inconspicuous, you can find every kind of bath thermometer. When considering the design, you should therefore ask yourself the following questions: How long do I want to use this thermometer? Is the thermometer for a baby or for an adult?

To give your baby the best care and the most fun while bathing, you can reliably check the temperature with a bath thermometer. (Image source: Honest Company)

When it comes to a bath thermometer for babies, you can choose a plain thermometer that serves its purpose or a colourful thermometer that also serves as a toy.

If you are looking for a bath thermometer for adults, you can choose according to your personal preferences. These are usually simpler and often in muted tones.


Generally speaking, digital bath thermometers can give you a slightly more accurate reading of the water temperature. However, this is usually due to the scale, not the temperature measurement itself.

The expansion of the liquid in analogue bath thermometers can be measured very accurately. The only difference is that the scale is usually only in 1 degree Celsius increments.

You can often tell whether the temperature is exactly 37 degrees or slightly above 37 degrees, for example, but analogue thermometers usually do not provide an exact measurement to one decimal place.

Digital bath thermometers, on the other hand, can show the temperature more accurately because the digital display is not a scale, but only shows the result. Many digital bath thermometers can even display up to two decimal places, for example 37.52 degrees Celsius.

Facts worth knowing about bath thermometers

How do I clean a bath thermometer?

There is little to consider when cleaning bath thermometers. Cleaning is recommended in order to be able to use the product in good condition for as long as possible.

Bath thermometers are actually very easy to care for. They are designed to be waterproof and insensitive.

Analogue bath thermometers in particular are easy to clean. After bathing, it is sufficient to rinse the thermometer in clear water to remove any bath additive or soap residue. Cleaning agents that remain on the thermometer could attack the plastic after a while.

Digital bath thermometers are also usually very easy to clean. For most of them, rinsing under clear water is sufficient to keep the thermometer in good working order in the long term. However, if in doubt, read the operating instructions again to avoid damage.

Can I measure the air temperature with my bath thermometer?

Most digital bath thermometers can also measure the air temperature with their sensor. Some can even measure and display humidity as well. You should find out beforehand whether your bath thermometer of choice also has these functions and possibly ask the manufacturer.

What do I do if my bath thermometer is broken?

Something breaks in every household. Whether it is an analogue or digital bath thermometer makes little difference.

First of all: don't panic. Nowadays, most bath thermometers no longer contain any dangerous liquids or substances.

In any case, make sure that you do not injure yourself with the individual parts of the broken thermometer. Glass is often still used, especially in analogue bath thermometers.

If you were about to take a bath, you will probably have to rely on your intuition without your bath thermometer. For digital bath thermometers, always have spare batteries at hand.

How do I dispose of a bath thermometer?

To find out where to dispose of your bath thermometer, you first have to find out what materials are used.

In the following table, we have summarised how and where you can dispose of your old bath thermometer.

Type Disposal
Analogue bath thermometers Household waste, possibly recycling
Digital bath thermometers Recycling

Older analogue bath thermometers may still contain mercury. In this case, your thermometer must be disposed of as hazardous waste, not as household waste.

This is what a recycling centre looks like. Here they separate what can be recycled and what has to be disposed of. (Image source:

Digital bath thermometers should be taken to the nearest recycling centre. Of course, you can also take analogue bath thermometers to the recycling centre. However, if your analogue thermometer contains sunflower oil or alcohol as a liquid, you can also dispose of it in your household waste.

Picture source: / Mikesphotos

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