DHT11 vs DHT22 vs AHT10: Accuracy per Rupee (2026)
DHT11 vs DHT22 vs AHT10: Accuracy per Rupee (2026)
Quick answer: Buy the DHT22 (Rs.100). Going from the DHT11 to the DHT22 costs Rs.55 and cuts temperature error from ±2°C to ±0.5°C — about Rs.37 per degree of error removed. Every step above that costs far more per degree. Buy the DHT11 (Rs.45) only for a classroom demo; buy the AHT10 (Rs.120) if you need I2C or a fast reading.
Written and fact-checked by Compoden's engineering team, India. Every accuracy figure, range and price below is read from our live catalogue record for the exact part named. The cost-per-degree numbers are our own arithmetic on those catalogue figures, not bench measurements. Published 18 August 2026 · Last updated 18 August 2026.
"Accuracy per rupee" sounds like a slogan until you actually divide. Four temperature-and-humidity sensors sit in the Rs.45-190 range in our catalogue, their specification sheets differ by a factor of nearly seven in stated temperature error, and the price differences between them are not proportional to the accuracy differences at all. One step on that ladder is outstanding value. The next is mediocre. The one after that buys you no accuracy whatsoever — it buys range and speed, which may or may not be what you needed.
| Spec | DHT11 | DHT22 (AM2302) | AHT10 | GY-SHT30-D |
|---|---|---|---|---|
| Price (India, COD) | Rs.45 | Rs.100 | Rs.120 | Rs.190 |
| Temperature accuracy (°C) | ±2 | ±0.5 | ±0.3 | ±0.3 |
| Humidity accuracy (% RH) | ±5 | ±2 | ±2 | ±2 |
| Temperature range (°C) | 0 to 50 | -40 to 80 | -40 to 85 | -40 to 125 |
| Humidity range (% RH) | 20 to 80 | 0 to 100 | 0 to 100 | 0 to 100 |
| Interface | Proprietary 1-wire | Proprietary 1-wire | I2C (0x38) | I2C (0x44) |
| Minimum read interval (ms) | 1,000 | 2,000 | 1,000 | 100 |
Verdict in one line: the DHT11 is the only one of the four that cannot cover a normal Indian summer indoors and a normal monsoon humidity, and it is the only one whose limits are a range problem rather than an accuracy problem.
What is the actual cost per degree of accuracy?
Divide the price step by the error it removes and the ladder stops being a straight line. Moving from the DHT11 (Rs.45, ±2°C) to the DHT22 (Rs.100, ±0.5°C) costs Rs.55 and removes 1.5°C of error — about Rs.37 per degree. Moving from the DHT22 to the AHT10 (Rs.120, ±0.3°C) costs Rs.20 and removes 0.2°C — about Rs.100 per degree, nearly three times worse value. Moving from the AHT10 to the GY-SHT30-D (Rs.190, ±0.3°C) costs Rs.70 and removes no temperature error at all; the two are specified identically on accuracy, and what the extra Rs.70 buys is a wider range and a much faster read. These are our own divisions of the accuracy and price fields in our catalogue records, not measurements — but the arithmetic is what tells you where the value stops.
Why is the DHT11 a bad choice in India specifically?
Its range, not its accuracy, is what rules it out. The DHT11 is specified for 0-50°C and 20-80% RH. Indian indoor temperatures sit comfortably inside that band — but 20-80% RH does not cover a monsoon, where indoor relative humidity routinely sits above 80%, nor a dry north-Indian winter afternoon below 20%. Outside its specified band a sensor does not fail loudly; it keeps returning plausible-looking numbers that are simply wrong, which is far worse for a data logger than an error. The DHT22 and both I2C parts cover 0-100% RH, so they stay inside specification through a monsoon. If your project logs humidity anywhere in coastal or monsoon India, this single row of the table decides it.
Where is the BME280 in this comparison?
We do not stock one, so it is not in the table — and that is the honest answer rather than a substituted spec sheet. The BME280 is the sensor most commonly named as the next step up from a DHT22, and if you specifically want temperature, humidity AND barometric pressure in one part, it is a reasonable thing to go looking for. What we do carry near it: the BMP280 at Rs.40, which measures pressure and temperature but not humidity (a substitution that catches people, because the names differ by one letter), and the BME680 at Rs.780, which measures temperature, humidity, pressure and VOC gas. Note the BME680's stated accuracy before you assume expensive means precise: ±1°C and ±3% RH, both looser than the DHT22's ±0.5°C and ±2% RH at one-eighth the price. It is a broader sensor, not a better thermometer.
Does the I2C interface matter more than the accuracy?
Often, yes — and it is the real reason to pay Rs.20 more for an AHT10 over a DHT22. Both DHT parts use a proprietary single-wire protocol that is not Dallas 1-Wire despite the name it is usually filed under: there is no addressing, so one sensor needs one dedicated GPIO pin, and you cannot put two on the same wire. The AHT10 and SHT30 are I2C devices at 0x38 and 0x44 respectively, sharing the same two pins with every other I2C part in your build — an OLED, an RTC, a second sensor. On a board where pins are scarce, or a project that already has an I2C bus running, the AHT10's Rs.100-per-degree accuracy step is beside the point; you are buying a bus, and the accuracy comes free.
Why does my DHT sensor return NaN or -999?
Almost always timing, not a dead sensor. Both DHT parts need a settling period of about 2 seconds after power-on or begin() before they will answer, and both enforce a minimum interval between reads — 1 second on the DHT11, 2 seconds on the DHT22. Read faster than that, or read immediately after begin(), and the library returns NaN. Our own catalogue records name this as the number one false "sensor faulty" report for both parts. The fix is to wait 2 seconds after begin(), keep at least the minimum interval between reads, and always wrap readings in an isnan() check rather than printing them raw. The DHT11 additionally needs a 4.7k-10k pull-up resistor on its data line, which many breakout boards include and bare sensors do not — the DHT22 module in our catalogue does not require an external one.
Which sensor is fast enough for a live display?
Not the DHT22, if "live" means more than once every two seconds. Response times in our records differ by more than two orders of magnitude: the DHT11 responds in about 1,000ms, the DHT22 in about 2,000ms, the AHT10 in about 10ms and the SHT30 in about 8ms. For a room monitor updating every minute this difference is invisible and irrelevant. For anything that reacts — a fan controller, a display that should not feel frozen, a process that needs several readings averaged quickly — the two I2C parts are in a different class entirely, and this, rather than the third decimal place of accuracy, is what the SHT30's Rs.190 actually buys alongside its -40 to 125°C range.
When is the DHT11 the right choice, honestly?
Two real cases, and they are narrower than its popularity suggests. First, teaching and demos: at Rs.45 it is the cheapest way to put a real digital sensor in thirty pairs of hands, its proprietary protocol is genuinely easy to drive with the Adafruit DHT library, and nobody is logging a monsoon in a two-hour class. Second, a coarse threshold where ±2°C simply does not matter — switching a fan on when a room passes "hot", where the decision has hysteresis measured in degrees anyway. What it is not is a data logger, a weather station, or anything whose readings you will later plot and believe.
Decision: which should you buy?
Default choice for almost any project: the DHT22 (AM2302) module (Rs.100) — the best value step on the ladder at about Rs.37 per degree of error removed. If your build already has an I2C bus, or is short of GPIO pins, or needs readings faster than every 2 seconds: the AHT10 module (Rs.120). If you need readings above 85°C or the fastest response here: the GY-SHT30-D module (Rs.190). And for a classroom set or a coarse threshold where ±2°C is fine: the DHT11 sensor (Rs.45). All four available cash on delivery across India.
What should you read next?
Ready to put one on a phone dashboard? Our ESP32 temperature and humidity web server build walks it end to end. If you are choosing an I2C part, our What Is I2C? guide covers addresses and the wiring errors that bite first.
Not sure which sensor your project needs? Open Soldr, describe what you are measuring and how often, and it will pick the sensor and the wiring.
Frequently asked questions
DHT11 aur DHT22 mein kya difference hai?
DHT22 kaafi zyada accurate hai: temperature mein ±0.5°C (DHT11 mein ±2°C) aur humidity mein ±2% RH (DHT11 mein ±5% RH). Range bhi behtar hai - DHT22 0-100% RH aur -40 se +80°C tak chalta hai, jabki DHT11 sirf 20-80% RH aur 0-50°C. Monsoon mein humidity 80% se upar chali jaati hai, isliye DHT11 galat readings dene lagta hai. Sirf Rs.55 ka farak hai (Rs.45 vs Rs.100) - DHT22 hi lein.
Is the BME280 better than the DHT22?
We do not stock a BME280, so we cannot quote you its price or verify its specs from our own catalogue — and we are not going to substitute a spec sheet we have not checked. What we can tell you is about the parts we do carry near it: the BMP280 (Rs.40) measures pressure and temperature but not humidity, despite the one-letter name difference, and the BME680 (Rs.780) measures temperature, humidity, pressure and VOC gas at a stated ±1°C and ±3% RH — looser on both than the DHT22's ±0.5°C and ±2% RH at Rs.100.
Why does my DHT sensor return NaN?
Usually because it was read too soon or too often, not because it is faulty. Both DHT parts need about 2 seconds to settle after power-on or begin(), and enforce a minimum read interval — 1 second for the DHT11, 2 seconds for the DHT22. Reading faster returns NaN. Our catalogue records name this as the top false "sensor faulty" report for both parts. Wait 2 seconds after begin(), respect the interval, and always isnan()-check the value before using it.
Can I put two DHT22 sensors on one pin?
No. The DHT11 and DHT22 use a proprietary single-wire protocol with no ROM and no addressing — despite often being filed under "1-Wire", it is not Dallas 1-Wire — so each sensor needs its own dedicated GPIO pin. If you need several sensors on shared wiring, use I2C parts instead: the AHT10 (address 0x38) and the SHT30 (0x44) share one SDA/SCL pair, though two of the same model on one bus will collide unless the model has an address-select pin.
What is the price of DHT11 and DHT22 in India?
At Compoden, the DHT11 Temperature & Humidity Sensor is Rs.45 and the DHT22 (AM2302) module is Rs.100. The I2C alternatives are the AHT10 at Rs.120 and the GY-SHT30-D at Rs.190. All four are available with cash on delivery across India. Prices checked August 2026.