---
title: "16.5 X 21.5 X1 Air Filter — $126K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/tools-home-improvement/16-5-x-21-5-x1-air-filter"
last_updated: "2026-08-08T08:53:00.668Z"
locale: en
meta:
description: "Niche score 43/100 · $126K/yr market · 19K searches/yr · $41.02 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 43/100 · $126K/yr market · 19K searches/yr · $41.02 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "16.5 X 21.5 X1 Air Filter — $126K/yr Amazon US Niche (2026) - Flapen"
---
# **16.5 x 21.5 x1 air filter**
**Skip it**
A concentrated shelf (top 5 take 100% of clicks) — this niche doesn't clear our bar today.
Market size 29Growth 55Conversion 97Competition 0Returns 76Price range 95Avg price 95Brand share 0Review moat 31Quality gap 21
**Conversion**
**Incredible****15.9%**
search→purchase rate — share of searches ending in a sale
**Avg price**
**Incredible****$41.02**
avg listing price — sweet spot $15–$100
**Price range**
**Incredible****$33.33–$54.91**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Great****2.0%**
return rate — above 5% kills the launch gate
**Growth**
**Good****+27.4%**
90-day search growth — must beat 0% to launch
**Review moat**
**Okay****3,366**
avg incumbent reviews — the moat a new listing must climb
**Market size**
**Okay****$126K**
$126K/yr · 19K searches
**Quality gap**
**Bad****4.7★**
avg incumbent rating — lower means beatable quality
**Competition**
**Bad****100%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****100%**
top-5 brand share — brand-locked demand
According to Flapen's Amazon United States niche tracking, 16.5 x 21.5 x1 air filter is a $126K/yr Amazon United States market (19K searches/yr). The top 5 brands hold 100% of demand. Demand peaks in Jan–Feb–Nov. Verdict: Skip it — 43/100.
Data updated Jul 27, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **16.5 x 21.5 x1 air filter market data**
- **Units sold / yr**
- **3K–3K**
- avg 250–500/product
- **Revenue / yr**
- **$103K–$123K**
- units × avg price
- **Conversion rate**
- **15.9%**
- **Avg BSR**
- **#94**
- **Page quality**
- **0%**
- **Prime**
- **80%**
- **Sponsored**
- **80%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **81 months**
- **Avg seller age**
- **217 days**
## **Competition & brand share**
The top 5 products capture 100% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**3 **▼falling
**Sellers**
**5**
**Top-5 brand share**
**100%**
Top 20: 100%
**Top-5 click share**
**100%**
Top 20: 100%
**Open market**
**0%**
- Aerostar57% - Filtrete39% - Filter King4%
## **Demand & seasonality**
Weekly Amazon search volume, last 102 weeks — +27.4% search growth over the last 90 days.
2K1KSpike '24Spike '25Prime Day '25Black Friday '25Spike '26 seasonDecMarJunAugNovMarMay
Peak months: Jan, Feb, Nov · busiest ÷ quietest = 2.4×
[**Open Trend **](https://flapen.com/research/us/tools-home-improvement/16-5-x-21-5-x1-air-filter/trend)
## **Top 16.5 x 21.5 x1 air filter search terms**
- **16.5x21.5x1 air filter**12K/yr+23.2%7.9% conv. - **16.5 x 21.5 x 1 air filter**4K/yr+35.0%8.3% conv. - **16 1/2 x 21 1/2 x 1 air filter**3K/yr+37.1%6.7% conv. [**All search terms **](https://flapen.com/research/us/tools-home-improvement/16-5-x-21-5-x1-air-filter/search-terms)
## **Top 16.5 x 21.5 x1 air filter 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%15%$19K30%$38K45%$57K60%$76K1K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 5 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Aerostar 16.5x21.5x1 MERV 8 - 6 Count - High Efficiency Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Lint Mold & Allergy-Causing Pollen**Aerostar**$37.93**4.6★2,445 rev](https://www.amazon.com/dp/B01CSWQ79U) [2**Filtrete 16.5x21.5x1 AC Furnace Air Filter MERV 8 MPR 700 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 16.19 x 21.19 x 0.81 in)**Filtrete**$38.62**4.7★6,265 rev](https://www.amazon.com/dp/B0CZBTYX4J) [3**Aerostar 16.375x21.5x1 MERV 11 Air Filter 4 Count ACTUAL SIZE (16.50 x 21.50 x 0.75) HVAC Air Conditioning & Furnace Filter for Dust Pet Dander Smoke & Allergies (MPR 1200 / FPR 7) Made in USA**Aerostar**$33.33**4.7★4,106 rev](https://www.amazon.com/dp/B0813SW6FK) [4**Filter King 16.5x21.5x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: : 16.5 x 21.5 x .75)**Filter King**$40.32**4.7★1,569 rev](https://www.amazon.com/dp/B0BJ4QLHJL) [5**Aerostar 16.5x21.5x1 MERV 11 - 6 Count - Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Cold & Flu Germs Lint Mold Pet Dander Allergy-Causing Pollen Smog & Smoke**Aerostar**$54.91**4.6★2,445 rev](https://www.amazon.com/dp/B01CR9JK8O)
### **Newest**
by launch date
[**Filtrete 16.5x21.5x1 AC Furnace Air Filter MERV 8 MPR 700 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 16.19 x 21.19 x 0.81 in)**Filtrete**$38.62**6,265 rev2y ago](https://www.amazon.com/dp/B0CZBTYX4J) [**Filter King 16.5x21.5x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: : 16.5 x 21.5 x .75)**Filter King**$40.32**1,569 rev3y ago](https://www.amazon.com/dp/B0BJ4QLHJL) [**Aerostar 16.375x21.5x1 MERV 11 Air Filter 4 Count ACTUAL SIZE (16.50 x 21.50 x 0.75) HVAC Air Conditioning & Furnace Filter for Dust Pet Dander Smoke & Allergies (MPR 1200 / FPR 7) Made in USA**Aerostar**$33.33**4,106 rev6y ago](https://www.amazon.com/dp/B0813SW6FK) [**Aerostar 16.5x21.5x1 MERV 8 - 6 Count - High Efficiency Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Lint Mold & Allergy-Causing Pollen**Aerostar**$37.93**2,445 rev10y ago](https://www.amazon.com/dp/B01CSWQ79U) [**Aerostar 16.5x21.5x1 MERV 11 - 6 Count - Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Cold & Flu Germs Lint Mold Pet Dander Allergy-Causing Pollen Smog & Smoke**Aerostar**$54.91**2,445 rev10y ago](https://www.amazon.com/dp/B01CR9JK8O)
### **Trending**
90-day click momentum
[**Aerostar 16.5x21.5x1 MERV 11 - 6 Count - Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Cold & Flu Germs Lint Mold Pet Dander Allergy-Causing Pollen Smog & Smoke**Aerostar**$54.91**4.6★**▲ 33%**](https://www.amazon.com/dp/B01CR9JK8O) [**Aerostar 16.5x21.5x1 MERV 8 - 6 Count - High Efficiency Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Lint Mold & Allergy-Causing Pollen**Aerostar**$37.93**4.6★**— 7%**](https://www.amazon.com/dp/B01CSWQ79U) [**Filtrete 16.5x21.5x1 AC Furnace Air Filter MERV 8 MPR 700 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 16.19 x 21.19 x 0.81 in)**Filtrete**$38.62**4.7★**— 6%**](https://www.amazon.com/dp/B0CZBTYX4J) [**Filter King 16.5x21.5x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: : 16.5 x 21.5 x .75)**Filter King**$40.32**4.7★**— 10%**](https://www.amazon.com/dp/B0BJ4QLHJL) [**Aerostar 16.375x21.5x1 MERV 11 Air Filter 4 Count ACTUAL SIZE (16.50 x 21.50 x 0.75) HVAC Air Conditioning & Furnace Filter for Dust Pet Dander Smoke & Allergies (MPR 1200 / FPR 7) Made in USA**Aerostar**$33.33**4.7★**▼ 38%**](https://www.amazon.com/dp/B0813SW6FK)
## **What buyers say about 16.5 x 21.5 x1 air filter**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Quality-Overall**36%
*“Good quality”*
**Filtration**19%
*“Really good filters”*
**Advertised Vs Actual Product**8%
*“As advertised”*
**Size-Overall**8%
*“They fit nicely, dont flop around. horizontal install., and do a good job catching small and large particles”*
**Value For Money**7%
*“Perfect and Great price”*
**Functionality-Overall**4%
*“do a good job catching small and large particles”*
**Ease Of Use**4%
*“Easy to use”*
**Storage Capacity**4%
*“love having a bulk supply”*
**Assembly/Installation**3%
*“So easy to install”*
**Color**3%
*“Love the color white also”*
### **What buyers complain about **
**Quality-Overall**22%
*“very cheap”*
**Filtration**11%
*“This filter is incredibly cheap and flimsy”*
**Size-Overall**11%
*“Was given the wrong size”*
**Strength**11%
*“Flimsy, very cheap”*
**Design-Overall**11%
*“Definite design flaw”*
**Assembly/Installation**11%
*“when it literally crumbles in your hand trying to install it, its garbage”*
### **Top return reasons **
**Size-Overall**63%
**Filtration**21%
**Compatibility-Overall**8%
**Defective Material/Parts**2%
**Value For Money**1%
**Quality-Overall**1%
**Advertised Vs Actual Product**1%
**Certifications**1%
**Thickness**1%
**Thin**0%
## **Common questions**
- **Is 16.5 x 21.5 x1 air filter profitable to sell on Amazon United States?**
- The niche generates $126K/yr across 5 tracked products. 90-day search growth is +27.4%. Flapen's verdict: Skip it (43/100).
- **How competitive is the 16.5 x 21.5 x1 air filter niche?**
- 3 brands and 5 sellers compete. The top 5 products take 100% of clicks and top 5 brands hold 100% of demand.
- **What do buyers complain about in 16.5 x 21.5 x1 air filter?**
- Top complaints mined from reviews: Quality-Overall, Filtration, Size-Overall. The return rate is 2.0%.
- **When does demand for 16.5 x 21.5 x1 air filter peak?**
- Demand peaks in Jan–Feb–Nov; the busiest month runs 2.4× the quietest.
- **What does it cost to enter the 16.5 x 21.5 x1 air filter niche?**
- Listings span $33.33–$54.91; the average listing price is $41.02 (sweet spot $15–$100). The average incumbent carries 3,366 reviews — the moat a new listing must climb.
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