Best Budget CO2 Monitors Under $75

Getting a genuine NDIR CO2 monitor for under $75 was nearly impossible a few years ago, but increased competition and sensor commoditization have brought prices down dramatically. While these ultra-budget monitors lack the polish and connectivity of premium devices, they provide the core functionality that matters: an accurate CO2 reading from a real NDIR infrared sensor. This is crucial because many cheap monitors use eCO2 estimation based on VOC sensors, which is wildly inaccurate for actual CO2 levels. Every monitor in our budget picks has been verified to use a genuine NDIR or photoacoustic CO2 sensor. If you are on a tight budget but refuse to compromise on measurement accuracy, these are your best options.

15 monitors rankedUpdated March 2026
1

Winsen MH-Z19C Module

Price: $25
Accuracy: ±50 ppm
Sensor: NDIR
CO2
2

SenseAir S8 Module

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

Kidde Nighthawk CO2 Monitor

Price: $55
Accuracy: ±30 ppm
Sensor: Electrochemical
CO2
8

Qingping Air Monitor Lite

Price: $60
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
9

Sensirion SCD41 Eval Kit

Price: $60
Accuracy: ±40 ppm
Sensor: Photoacoustic
CO2TemperatureHumidity
10

Thirdreality Smart CO2 Sensor

Price: $60
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
11

GZAIR Model A

Price: $65
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
12

CO2.Click CO2.Click

Price: $70
Accuracy: ±50 ppm
Sensor: NDIR
CO2
13

Ecowitt WH45

Price: $70
Accuracy: ±75 ppm
Sensor: NDIR
CO2PM2.5PM10TemperatureHumidity
14

TFA Dostmann AirCO2ntrol Mini

Price: $75
Accuracy: ±75 ppm
Sensor: NDIR
CO2
15

Yeelight YLCG01YL CO2 Sensor

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

Buying Tips: Best Budget CO2 Monitors Under $75

  • 1

    At this price, the most important thing to verify is that the monitor uses a true NDIR CO2 sensor, not an eCO2 or estimated CO2 sensor derived from VOC readings.

  • 2

    Do not expect WiFi, Bluetooth, or data logging at this price point. Most budget monitors are display-only, which is perfectly fine for basic ventilation awareness.

  • 3

    Accuracy will typically be ±75-100 ppm rather than ±30-50 ppm found in premium monitors, but this is still more than adequate for determining whether a room is well-ventilated.

  • 4

    Many of the cheapest monitors are available as DIY kits or sensor modules. If you are comfortable with basic electronics, these offer the best price-to-accuracy ratio available.

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