---
title: "Hydrometer — $473K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/patio-lawn-garden/hydrometer"
last_updated: "2026-08-11T05:58:01.605Z"
locale: en
meta:
description: "Niche score 60/100 · $473K/yr market. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
"og:description": "Niche score 60/100 · $473K/yr market. A failed launch gate (market size, growth, or returns) keeps it on the watch list. Data updated Jul 2026."
"og:title": "Hydrometer — $473K/yr Amazon US Niche (2026) - Flapen"
---
# **hydrometer**
**Worth a look**
Shows low returns (1.2%), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.
Market size 59Growth 19Conversion 88Competition 72Returns 91Price range 47Avg price 55Brand share 81Review moat 20Quality gap 52
**Returns**
**Great****1.2%**
return rate — above 5% kills the launch gate
**Conversion**
**Great****10.2%**
search→purchase rate — share of searches ending in a sale
**Brand share**
**Great****54%**
top-5 brand share — no brand owns this niche
**Competition**
**Good****42%**
top-5 click share — leaders hold, buyers still browse
**Market size**
**Good****$473K**
$473K/yr · 365K searches
**Avg price**
**Good****$12.65**
avg listing price — sweet spot $15–$100
**Quality gap**
**Good****4.4★**
avg incumbent rating — lower means beatable quality
**Price range**
**Okay****$5.97–$22.94**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Review moat**
**Bad****12,296.39**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Bad****-12.3%**
90-day search growth — must beat 0% to launch
**Signals**[** No Dominant Brand**](https://flapen.com/research/niches?market=us&signal=no_dominant_brand "Top brand's click share < 20%")
According to Flapen's Amazon United States niche tracking, hydrometer is a $473K/yr Amazon United States market (365K searches/yr). The top 5 brands hold 54% of demand. Verdict: Worth a look — 60/100.
Data updated Jul 15, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **hydrometer market data**
- **Units sold / yr**
- **30K–40K**
- avg 1,000–1,250/product
- **Revenue / yr**
- **$380K–$506K**
- units × avg price
- **Conversion rate**
- **10.2%**
- **Avg BSR**
- **#13**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **94%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **61 months**
- **Avg seller age**
- **183 days**
## **Competition & brand share**
The top 5 products take 42% of clicks — established leaders, but buyers still shop beyond them.
**Brands**
**26 **▲rising
**Sellers**
**51**
**Top-5 brand share**
**54%**
Top 20: 96%
**Top-5 click share**
**42%**
Top 20: 86%
**Open market**
**39%**
- Brewer's Elite15% - TempPro14% - Serundo Auto10% - KOSOEUR8% - ANFBYOH8% - JEDEW6%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -12.3% search growth over the last 90 days.
8K6KPrime Day '25 seasonSepDecMarJunAugNovMarMay
No pronounced peak months · busiest ÷ quietest = 1.3×
[**Open Trend **](https://flapen.com/research/us/patio-lawn-garden/hydrometer/trend)
## **Top hydrometer search terms**
- **hydrometer**353K/yr-12.3%8.8% conv. - **hydrometers**7K/yr-12.6%7.8% conv. - **hydro meter**3K/yr-15.3%7.4% conv. - **hidrometro**2K/yr-6.3%2.7% conv. [**All search terms **](https://flapen.com/research/us/patio-lawn-garden/hydrometer/search-terms)
## **Top hydrometer products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%3%$14K6%$28K9%$43K12%$57K101001K10K100K1.0M Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Mini Hygrometer Thermometer Digital Humidity Meter Indoor/Outdoor Humidity Monitor Reptile Thermometer for Greenhouse Garden Cellar Fahrenheit()/ Celsius() 2 Pack**Serundo Auto**$5.97**4.5★3,331 rev](https://www.amazon.com/dp/B0CXHV22GD) [2**Brewers Elite Hydrometer for Home Brew Beer Wine Mead and Kombucha - Deluxe Triple Scale Set with Hardcase and Cloth - Specific Gravity ABV Tester**Brewer's Elite**$13.01**4.4★5,544 rev](https://www.amazon.com/dp/B01CITP03W) [3**TempPro TP50 Digital Hygrometer Indoor Thermometer Room Thermometer and Humidity Gauge with Temperature Humidity Monitor(Previously ThermoPro)**TempPro**$10.88**4.6★154,357 rev](https://www.amazon.com/dp/B01H1R0K68) [4**6-Pack Mini Hygrometer Indoor Humidity Meter Mini Digital Thermometer Humidity Gauge Meter Indoor Thermometer Hygrometer Monitor Fahrenheit () for Reptile Thermostat Jars Reptile Fridge**ANFBYOH**$8.12**4.5★1,920 rev](https://www.amazon.com/dp/B0CXHS6CYS) [5**Kosoeur Triple Scale Hydrometer Alcohol Hydrometer for Wine Mead Kombucha & Beer Mead Making Kit (ABV Tester Brix Specific Gravity Hydrometer) Hydrometer Alcohol Kit for Wine Brewing Supplies**KOSOEUR**$10.50**4.3★362 rev](https://www.amazon.com/dp/B0CBJKSXP7)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**CIMALAB Triple Scale Hydrometer Specific Gravity Hydrometer for Wine Making Mead Kombucha & Beer Mead Making Kit ABV Tester Brix Tester Hydrometer Alcohol Tester for Wine Making Supplies**CIMALAB**$10.85**38 rev11mo ago](https://www.amazon.com/dp/B0F38899Z4) [**6 Pack Mini Hygrometer Indoor Humidity Meter Small Digital Thermometer Humidity Gauge Meter Indoor Thermometer Hygrometer Monitor Fahrenheit () for Thermostat Reptile Tank Mason Jars**JJMTDS**$7.16**1,586 rev1y ago](https://www.amazon.com/dp/B0DNKGBW54) [**WWHAKO 4-Pack Mini Hygrometer Thermometer Indoor Outdoor Round Humidity Meter Small Digital LCD Monitor Thermometer Temperature Gauge Humidity Sensor () or () for Reptile Thermostat Jars**wwhako**$7.94**714 rev1y ago](https://www.amazon.com/dp/B0DG8ZXZ5D) [**Mini Hygrometer Thermometer Digital Humidity Meter Indoor/Outdoor Humidity Monitor Reptile Thermometer for Greenhouse Garden Cellar Fahrenheit()/ Celsius() 2 Pack**Serundo Auto**$5.97**3,331 rev2y ago](https://www.amazon.com/dp/B0CXHV22GD) [**6-Pack Mini Hygrometer Indoor Humidity Meter Mini Digital Thermometer Humidity Gauge Meter Indoor Thermometer Hygrometer Monitor Fahrenheit () for Reptile Thermostat Jars Reptile Fridge**ANFBYOH**$8.12**1,920 rev2y ago](https://www.amazon.com/dp/B0CXHS6CYS)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Hydrometer for Wine Making with 100 MM Hydrometer Alcohol Test Jar - Specific Gravity Hydrometer for Wine and Beer Making Testing Kit and Brewing Your Own Homebrew**Thermometer World**$10.02**4.5★**▲ 293%**](https://www.amazon.com/dp/B07RQZHWZ2) [**AOZ LIbei Hydrometer Set - for Mead Wine Kombucha and Home Brew Beer Alcohol Tester Accessories Moonshine Still Kit Complete for Home Test Equipment-Specific Gravity Abv Tester**AOZ LIbei**$22.12**4.5★**▲ 186%**](https://www.amazon.com/dp/B0CNXJB97X) [**Hydrometer - Alcohol 0-200 Proof and Tralle**Home Brew Stuff**$6.73**4.5★**▲ 119%**](https://www.amazon.com/dp/B013S1VAM4) [**CIMALAB Triple Scale Hydrometer Specific Gravity Hydrometer for Wine Making Mead Kombucha & Beer Mead Making Kit ABV Tester Brix Tester Hydrometer Alcohol Tester for Wine Making Supplies**CIMALAB**$10.85**4.3★**▲ 95%**](https://www.amazon.com/dp/B0F38899Z4) [**JEDEW 4 Pack Hygrometer Thermometer Digital Humidity Meter Indoor/Outdoor Humidity Monitor Reptile Thermo-Hygrometer for Greenhouse Humidors Terrarium Jars Fahrenheit () /Celsius() (4)**JEDEW**$9.50**4.5★**▲ 77%**](https://www.amazon.com/dp/B07GR67G1M)
**~~View all trending →~~**
## **What buyers say about hydrometer**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Value For Money**17%
*“Great deal”*
**Advertised Vs Actual Product**13%
*“Better than expected”*
**Quality-Overall**12%
*“Excellent Product”*
**Ease Of Use**12%
*“Easy to Read”*
**Efficiency**8%
*“Does its job well”*
**Size-Overall**6%
*“Fit great”*
**Measurement/Reading Accuracy**3%
*“Seems accurate”*
**Battery Life**3%
*“Battery life is good so far”*
**Temperature Control**2%
*“Temperature is accurate”*
**Durability**2%
*“Durable and accurate”*
### **What buyers complain about **
**Size-Overall**16%
*“Little bigger than I wanted”*
**Measurement/Reading Accuracy**12%
*“Inaccurate readings”*
**Quality-Overall**9%
*“Bad quality control”*
**Durability**8%
*“Doesn't Last”*
**Battery Life**7%
*“batteries don't last very long”*
**Functionality-Overall**6%
*“Did Not Work”*
**Connectivity-Overall**4%
*“Doesnt connect to app”*
**Value For Money**3%
*“Too expensive”*
**Display-Overall**3%
*“Display broken”*
**Advertised Vs Actual Product**2%
*“False advertising”*
### **Top return reasons **
**Size-Overall**16%
**Functionality-Overall**15%
**Measurement/Reading Accuracy**14%
**Connectivity-Overall**11%
**Advertised Vs Actual Product**9%
**Display-Overall**7%
**Defective Material/Parts**6%
**Value For Money**5%
**Heating**4%
**Compatibility-Overall**2%
## **Common questions**
- **Is hydrometer profitable to sell on Amazon United States?**
- The niche generates $473K/yr across 36 tracked products. 0 of 1 products launched in the last 360 days are still selling. 90-day search growth is -12.3%. Flapen's verdict: Worth a look (60/100).
- **How competitive is the hydrometer niche?**
- 26 brands and 51 sellers compete. The top 5 products take 42% of clicks and top 5 brands hold 54% of demand.
- **What do buyers complain about in hydrometer?**
- Top complaints mined from reviews: Size-Overall, Measurement/Reading Accuracy, Quality-Overall. The return rate is 1.2%.
- **When does demand for hydrometer peak?**
- Demand is steady year-round — the busiest month runs 1.3× the quietest.
- **What does it cost to enter the hydrometer niche?**
- Listings span $5.97–$22.94; the average listing price is $12.65 (sweet spot $15–$100). The average incumbent carries 12,296 reviews — the moat a new listing must climb.
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