Last Updated on September 17, 2022 by John Robinson
A majority of drivers want a good quality sound experience while they are on the road. This means that car stereos have gone from providing just an acceptable listening pleasure to delivering a high-fidelity and immersive virtual surround sound experience.
This upgrade in performance is possible only if car stereos operate at higher power levels, which help them produce louder sounds and more distinct bass.
This is where the question of how many watts is good for a car stereo comes into play. You need to know what wattage ratings mean in order to answer that question accurately. This article aims at providing you with all the information you need on this subject matter.
What is Wattage Rating?
The wattage rating of a car stereo or amplifier is defined as its power output in RMS watts. The abbreviation for this measurement is RMS, which stands for Root Mean Square. In simple terms, this means that the given wattage rating is what you can expect from the car stereo when it operates on average volume conditions.
Car stereos deliver a range of wattage ratings. The extent of this power variation is dependent on the type of vehicle in which they are installed and their size. For instance, if you have a factory-fitted stereo system, you will notice that it has a relatively low wattage rating. In fact, it is usually less than 10 watts RMS. The lowest wattage rating for car stereos is 5 watts RMS, which is mostly seen in the simplest of factory-fitted stereo systems.
However, if you are opting for an aftermarket upgrade to your vehicle’s existing sound system, pick a model that has good power ratings like 30-40 watt RMS per channel. This will ensure that you get the best possible sound quality from your car stereo.
How Many Watts is Good for a Car Stereo?

Now that you understand what wattage ratings mean, it is easy to answer the question of how many watts is good for a car stereo. A good wattage rating for an aftermarket car stereo is one that is higher than the factory-fitted stereo system. This will ensure that you get a noticeable improvement in sound quality.
If you have a factory-fitted stereo system with a wattage rating of 10 watts RMS per channel, then you should opt for an aftermarket car stereo that has a wattage rating of 30-40 watt RMS per channel. This will give you a significant improvement in sound quality and allow you to enjoy your music to the fullest.
What are the benefits of a higher wattage?
There are a few benefits that come with using a car stereo that has a higher wattage rating.
- Firstly, it allows you to push your speakers to their limits and this in turn produces louder and cleaner sound.
- Secondly, it can help improve the overall performance of your vehicle’s audio system. This is because a more powerful stereo can drive speakers that are of a higher impedance rating as compared to those that are driven by a factory-installed stereo.
- Lastly, it can also help protect your speakers from damage. This is because a more powerful stereo can prevent them from being overdriven, which can lead to speaker failure.
What are the drawbacks of having a higher wattage?
A higher wattage rating is considered to be beneficial. But there are also some disadvantages that come with it as well.
- Each additional watt requires more space on your vehicle’s electrical system, which can affect the overall performance of your existing equipment.
- Some car stereos with higher wattage ratings use an amplifier within the unit itself to drive speakers; this means that its output is divided between two channels. This can result in an underwhelming audio experience when compared to a mono-bridgeable unit, which provides better sound quality and more power to one speaker.
- High-wattage car stereos are expensive as they tend to be more advanced than their lower wattage counterparts. This is because they utilize advanced technology such as DSP (digital signal processing), BT (Bluetooth) systems and USB ports for connectivity purposes.
- Most high-wattage car stereos are not compatible with a wide variety of vehicles. This is because they require additional components, such as an amplifier, to function properly.
Terms You Need to Know

- Peak Wattage: The peak wattage rating is the maximum power that a stereo can deliver for a brief period of time. This number is never an indication of the stereo’s true power. It is important to remember that the peak wattage rating should never be used to determine the power needs of a car stereo system. The RMS wattage rating, on the other hand, is a more accurate measure of how much power a car stereo can deliver at all times.
- RMS Wattage: RMS stands for Root Mean Square which is a mathematical formula that calculates the value of a varying phenomenon by taking its square root. In this context, it refers to the continuous power output a speaker can handle without being damaged. The RMS wattage rating provides you with an indication of how much power your car stereo will handle consistently. While it is no doubt that RMS wattage ratings are important, they don’t provide you with any information about the peak power that speakers can handle. This is where the Peak Power Rating (PPR) comes into play.
- Peak Power Rating: As mentioned before, this is the maximum power a car stereo can produce at a given point in time. Although not as important as RMS wattage ratings, Peak Power Rating provides you with an idea of how much power your speakers will handle for split seconds. It is nothing but the amount of energy that comes out of your speaker and it is usually more than the RMS wattage.
- Speaker Impedance: This is the measurement of electric resistance that a speaker presents to the flow of current. Car stereo’s usually come with speakers that are either 4Ω or 2Ω rated while their RMS wattage ratings can be found in manufacturer guidebooks. The impedance value not only tells you about the ability of your stereo to handle different types of loads, but also the Ohm rating of the speaker.
- Amps: An amp is a device that is used to increase the power of a signal. It is short for Amplifier. There are two types of amps when it comes to car stereos- an amplifier and a head unit. While the head unit is responsible for all the processing that goes on in your stereo, the amplifier is responsible for delivering the power to your speakers. It makes sense to mention this here because it is important to know if your stereo has an amplifier and how much power it delivers. A larger number signifies that the stereo will be able to drive a greater amount of power than a smaller one can. If you see amps mentioned in watts, then divide the number by 10 in order to get the actual amount of power your amp can deliver.
How Many Watts Does My Factory Car stereo Have?

When it comes to factory car stereos, you need to know that they have lower wattage ratings as compared to those from aftermarket manufacturers. This is because they have been designed not only to take less space in the dashboard area but also to consume less power so as to reduce their impact on your vehicle’s battery. In order to determine the peak power your factory-installed deck can handle, you need to know its peak voltage output. You can find this by multiplying the RMS voltage of your car stereo with the square root of 2.
So if you have a 12 V system in your car, you should expect about 41 W from it. This is because most factory car stereos use of 4Ω speakers with their RMS wattage ratings of 50 watts. So, by multiplying the voltage (12 V) with the square root of 2 (which is roughly 30), you get about 41 W.
What Wattage Is Suitable For A Car Stereo?
The general rule is that the RMS wattage of your car stereo should be equal to or greater than the number mentioned on your speaker’s label. If you are looking for a good quality sound when playing music in your vehicle, then you need to ensure that your speakers can handle enough power so as to give you crisp and clear sound. If your car stereo is rated to deliver 30 W RMS at 4Ω, then you should make sure that the power output of your speakers is similar or higher than this number.
Frequently Asked Questions
How many watts do car stereos use?
Generally, a car stereo can use anywhere from 10 watts to 1000 watts RMS. However, most systems that come with an aftermarket deck tend to have a wattage rating between 20 and 50 W RMS. The majority of factory-installed systems deliver less power than this as their primary goal is to save space and reduce costs. In fact, some vehicles only have a single speaker working off the head unit itself.
Is it a good idea to run a car stereo with a higher wattage than the battery?
No, it is not a good idea to run a car stereo with a higher wattage than the battery. This is because it can overload the electrical system and cause damage to your vehicle’s components. So, it is important to make sure that the stereo you are planning to buy has a wattage rating that is within the range of your vehicle’s battery. Additionally, it is also important to ensure that all of your audio equipment is properly grounded in order to prevent any shorts from occurring.
What is the best wattage for a car stereo?
The best wattage for a car stereo depends on the type of system you are looking to install. If you are just looking to replace your old deck, then a stereo with a wattage rating between 20 and 50 W RMS should be sufficient. However, if you are looking to add amplifiers and subwoofers to your system, then you will need a stereo that can deliver more power. In this case, a unit with a wattage rating of 100 W RMS or more would be ideal.