Best CO2 Monitors Under $100
You do not need to spend hundreds of dollars to get a reliable CO2 monitor. Several excellent options exist under $100 that use genuine NDIR sensors, which is the gold standard for accurate CO2 measurement. These budget monitors are ideal for anyone who wants to track ventilation quality at home or in a small office without breaking the bank. While they may lack advanced features like WiFi connectivity or multi-pollutant sensing, they deliver the core CO2 readings you need to maintain healthy indoor air. We have tested and compared the most popular sub-$100 options to help you pick the right one.
How We Picked
We screened all 24 monitors in our directory that qualify for this list and ranked the top 10. Selection weights sensor type first (NDIR and photoacoustic only — no eCO2 estimates), then published accuracy, then the features that specifically matter for co2 monitors under $100. Prices are typical street prices and move often; we re-check them monthly.
INKBIRD IAM-T1
Best overallAt $80 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
Qingping Air Monitor Lite
Runner-upAt $60 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
INKBIRD CO2 Monitor
At $50 this sits near the floor of the sub-$100 bracket. It holds ±100 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
TFA Dostmann AirCO2ntrol Mini
At $75 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
Temtop M10
At $90 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
CO2.Click CO2.Click
At $70 this sits comfortably inside the sub-$100 bracket. It holds ±50 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
ThermoPro TP-65A CO2
At $90 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
Ecowitt WH45
At $70 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. There is no display, so you are dependent on the app — check it works on your phone before buying.
AcuRite Indoor Air Quality Monitor
At $85 this sits comfortably inside the sub-$100 bracket. It holds ±75 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
PJRC CO2 Gadget DIY Kit
Best valueAt $45 this sits near the floor of the sub-$100 bracket. It holds ±50 ppm, which is the part budget monitors usually compromise on. The built-in display matters here, because nothing at this price ships a reliable app.
Buying Tips: Best CO2 Monitors Under $100
- 1
Make sure the monitor uses an NDIR sensor, not a cheaper eCO2 (estimated CO2) sensor that calculates CO2 from VOC levels and is far less accurate.
- 2
A built-in display is almost essential at this price range since most budget monitors lack app connectivity, so the screen is your only way to read data.
- 3
Check whether the device needs a USB power source or runs on batteries. Battery-free options are fine for stationary desk use but limit portability.
- 4
Look for monitors that show temperature and humidity alongside CO2, giving you a more complete picture of your indoor environment at no extra cost.