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.

24 monitors rankedUpdated March 2026
1

Ecowitt WH45

Price: $70
Accuracy: ±75 ppm
Sensor: NDIR
CO2PM2.5PM10TemperatureHumidity
2

AcuRite Indoor Air Quality Monitor

Price: $85
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidityVOC
3

PJRC CO2 Gadget DIY Kit

Price: $45
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
4

Vson WP6912

Price: $45
Accuracy: ±100 ppm
Sensor: NDIR
CO2TemperatureHumidity
5

INKBIRD CO2 Monitor

Price: $50
Accuracy: ±100 ppm
Sensor: NDIR
CO2TemperatureHumidity
6

Seben HT-2000

Price: $55
Accuracy: ±100 ppm
Sensor: NDIR
CO2TemperatureHumidity
7

Qingping Air Monitor Lite

Price: $60
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
8

Sensirion SCD41 Eval Kit

Price: $60
Accuracy: ±40 ppm
Sensor: Photoacoustic
CO2TemperatureHumidity
9

Thirdreality Smart CO2 Sensor

Price: $60
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
10

GZAIR Model A

Price: $65
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
11

Yeelight YLCG01YL CO2 Sensor

Price: $75
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
12

INKBIRD IAM-T1

Price: $80
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
13

GZAIR Model B

Price: $85
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
14

Pyle PACO2

Price: $85
Accuracy: ±100 ppm
Sensor: NDIR
CO2TemperatureHumidity
15

Temtop M10

Price: $90
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
16

ThermoPro TP-65A CO2

Price: $90
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
17

Technoline WL1030

Price: $95
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
18

Winsen MH-Z19C Module

Price: $25
Accuracy: ±50 ppm
Sensor: NDIR
CO2
19

SenseAir S8 Module

Price: $40
Accuracy: ±40 ppm
Sensor: NDIR
CO2
20

Kidde Nighthawk CO2 Monitor

Price: $55
Accuracy: ±30 ppm
Sensor: Electrochemical
CO2
21

CO2.Click CO2.Click

Price: $70
Accuracy: ±50 ppm
Sensor: NDIR
CO2
22

TFA Dostmann AirCO2ntrol Mini

Price: $75
Accuracy: ±75 ppm
Sensor: NDIR
CO2
23

SenseAir K-30

Price: $85
Accuracy: ±30 ppm
Sensor: NDIR
CO2
24

Telaire T6613

Price: $95
Accuracy: ±50 ppm
Sensor: NDIR
CO2

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.

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