---
title: "13x21.5x1 Air Filter — $86K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/tools-home-improvement/13x21-5x1-air-filter"
last_updated: "2026-08-08T06:59:21.901Z"
locale: en
meta:
description: "Niche score 48/100 · $86K/yr market · 28K searches/yr · $41.77 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 48/100 · $86K/yr market · 28K searches/yr · $41.77 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "13x21.5x1 Air Filter — $86K/yr Amazon US Niche (2026) - Flapen"
---
# **13x21.5x1 air filter**
**Skip it**
Brand-locked demand (top 5 brands take 96% of clicks) — this niche doesn't clear our bar today.
Market size 21Growth 71Conversion 76Competition 20Returns 99Price range 95Avg price 95Brand share 10Review moat 19Quality gap 22
**Returns**
**Incredible****0.2%**
return rate — above 5% kills the launch gate
**Avg price**
**Incredible****$41.77**
avg listing price — sweet spot $15–$100
**Price range**
**Incredible****$26.55–$60.18**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Conversion**
**Great****7.2%**
search→purchase rate — share of searches ending in a sale
**Growth**
**Good****+53.2%**
90-day search growth — must beat 0% to launch
**Quality gap**
**Bad****4.7★**
avg incumbent rating — lower means beatable quality
**Market size**
**Bad****$86K**
$86K/yr · 28K searches
**Competition**
**Bad****76%**
top-5 click share — a locked-up shelf
**Review moat**
**Bad****14,247.44**
avg incumbent reviews — the moat a new listing must climb
**Brand share**
**Bad****96%**
top-5 brand share — brand-locked demand
According to Flapen's Amazon United States niche tracking, 13x21.5x1 air filter is a $86K/yr Amazon United States market (28K searches/yr). The top 5 brands hold 96% of demand. Demand peaks in Jun–Jul. Verdict: Skip it — 48/100.
Data updated Jul 27, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **13x21.5x1 air filter market data**
- **Units sold / yr**
- **3K–3K**
- avg 100–250/product
- **Revenue / yr**
- **$104K–$125K**
- units × avg price
- **Conversion rate**
- **7.2%**
- **Avg BSR**
- **#241**
- **Page quality**
- **0%**
- **Prime**
- **25%**
- **Sponsored**
- **75%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **71 months**
- **Avg seller age**
- **197 days**
## **Competition & brand share**
The top 5 products capture 76% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**7 **—flat
**Sellers**
**10**
**Top-5 brand share**
**96%**
Top 20: 100%
**Top-5 click share**
**76%**
Top 20: 100%
**Open market**
**2%**
- Filterbuy34% - Filtrete28% - Filter King25% - Aerostar7% - AIRx Filters2% - Simply2% - Open — no brand owns it (1 brand, 2%)
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +53.2% search growth over the last 90 days.
1K600Spike '25Prime Day '25Black Friday '25Holiday '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jun, Jul · busiest ÷ quietest = 2.2×
[**Open Trend **](https://flapen.com/research/us/tools-home-improvement/13x21-5x1-air-filter/trend)
## **Top 13x21.5x1 air filter search terms**
- **13x21.5x1 air filter**15K/yr+49.1%10.2% conv. - **air filter 13x21.5x1**6K/yr+56.9%6.7% conv. - **furnace filters 13x21.5x1**4K/yr+55.6%1.6% conv. - **13x21.5x1 furnace filter**4K/yr+59.8%0.9% conv. [**All search terms **](https://flapen.com/research/us/tools-home-improvement/13x21-5x1-air-filter/search-terms)
## **Top 13x21.5x1 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%10%$9K20%$17K30%$26K40%$34K1101001K10K100K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 16 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Filtrete 13x21.5x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 2-Pack (Actual Size 12.69 x 21.19 x 0.81 in)**Filtrete**$26.55**4.7★740 rev](https://www.amazon.com/dp/B0F9LTGHKV) [2**Filter King 13x21.5x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 13 x 21.5 x .75)**Filter King**$39.45**4.7★4,436 rev](https://www.amazon.com/dp/B07FQVYX2R) [3**Filterbuy 13x21.5x1 Air Filter MERV 8 Essential Dust & Allergy Defense (4-Pack) Electrostatic Pleated HVAC AC Furnace Filters Replacement Made in USA (Actual Size: 12.88 x 21.50 x 0.75)**Filterbuy**$44.87**4.7★703 rev](https://www.amazon.com/dp/B00CJZ7R14) [4**Aerostar 13x21.5x1 MERV 8 Pleated Air Filter 4 Pack AC Furnace Filters HVAC Filter Air Conditioner Filters Heater Filters Replacement for Home (Actual Size: 12.875x21.5x0.75)**Aerostar**$44.12**4.7★1,155 rev](https://www.amazon.com/dp/B07F1VXZY5) [5**Filterbuy 13x21.5x1 Air Filter MERV 8 Essential Dust & Allergy Defense (3-Pack) Electrostatic Pleated HVAC AC Furnace Filters Replacement Made in USA (Actual Size: 12.88 x 21.50 x 0.75)**Filterbuy**$36.60**4.7★9,643 rev](https://www.amazon.com/dp/B09B48KZZL)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Filtrete 13x21.5x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 2-Pack (Actual Size 12.69 x 21.19 x 0.81 in)**Filtrete**$26.55**740 rev1y ago](https://www.amazon.com/dp/B0F9LTGHKV) [**Filtrete 13x21.5x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 12.69 x 21.19 x 0.81 in)**Filtrete**$42.95**6,265 rev1y ago](https://www.amazon.com/dp/B0F9LTRT2T) [**Filtrete 13.5x21.5x1 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 13.187 x 21.187 x 0.81 in)**Filtrete**$42.12**6,265 rev2y ago](https://www.amazon.com/dp/B0CZC9KMHJ) [**AIRx Filters 13x21.5x1 Furnace Filter MERV 8 Electrostatic Pleated Replacement HVAC AC Air Filter with Advanced Filtration Technology 6-Pack**AIRx Filters**$47.64**4 rev2y ago](https://www.amazon.com/dp/B0CF7WHW2M) [**Filterbuy 13x21.5x1 Air Filter MERV 8 Essential Dust & Allergy Defense (3-Pack) Electrostatic Pleated HVAC AC Furnace Filters Replacement Made in USA (Actual Size: 12.88 x 21.50 x 0.75)**Filterbuy**$36.60**9,643 rev3y ago](https://www.amazon.com/dp/B09B48KZZL)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**AIRx Filters 13x21.5x1 Furnace Filter MERV 8 Electrostatic Pleated Replacement HVAC AC Air Filter with Advanced Filtration Technology 6-Pack**AIRx Filters**$47.64**5.0★**▲ 131%**](https://www.amazon.com/dp/B0CF7WHW2M) [**Filter King 13x21.5x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 13 x 21.5 x .75)**Filter King**$39.45**4.7★**▲ 105%**](https://www.amazon.com/dp/B07FQVYX2R) [**Aerostar 13x21 1/2x1 MERV 11 Pleated Air Filter 13 x 21 1/2 x 1 Box of 4 Made in The USA**Aerostar**$40.54**4.7★**▲ 57%**](https://www.amazon.com/dp/B07F1Z865L) [**SpiroPure 13x21.5x1 MERV 8 Air Filters for HVAC Pleated 6 Pack Made in USA**SpiroPure**$44.63**3.9★**▲ 32%**](https://www.amazon.com/dp/B07R6HBYQJ) [**Filtrete 13x21.5x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 2-Pack (Actual Size 12.69 x 21.19 x 0.81 in)**Filtrete**$26.55**4.7★**▲ 17%**](https://www.amazon.com/dp/B0F9LTGHKV)
**~~View all trending →~~**
## **What buyers say about 13x21.5x1 air filter**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**27%
*“Fit great”*
**Value For Money**23%
*“Good price point”*
**Filtration**13%
*“Good filter”*
**Quality-Overall**13%
*“Good product”*
**Advertised Vs Actual Product**6%
*“working as they should”*
**Allergies**6%
*“From an allergy and air-quality standpoint, I am incredibly happy with this purchase”*
### **What buyers complain about **
**Strength**33%
*“are super flimsy”*
**Quality-Overall**11%
*“But, I have one, maybe petty complaint”*
**Filtration**11%
*“Hard to find a 13x21.5 filter anywhere in person around me”*
**Value For Money**11%
*“all the ones online are kindve pricey with the exception of the 6-12 packs which I cant afford all at once tbh”*
### **Top return reasons **
**Size-Overall**75%
**Compatibility-Overall**8%
**Filtration**7%
**Assembly/Installation**3%
**Certifications**2%
**Functionality-Overall**2%
**Thickness**2%
**Maintenance And Repair**1%
**Defective Material/Parts**1%
**Advertised Vs Actual Product**1%
## **Common questions**
- **Is 13x21.5x1 air filter profitable to sell on Amazon United States?**
- The niche generates $86K/yr across 16 tracked products. 90-day search growth is +53.2%. Flapen's verdict: Skip it (48/100).
- **How competitive is the 13x21.5x1 air filter niche?**
- 7 brands and 10 sellers compete. The top 5 products take 76% of clicks and top 5 brands hold 96% of demand.
- **What do buyers complain about in 13x21.5x1 air filter?**
- Top complaints mined from reviews: Strength, Quality-Overall, Filtration. The return rate is 0.2%.
- **When does demand for 13x21.5x1 air filter peak?**
- Demand peaks in Jun–Jul; the busiest month runs 2.2× the quietest.
- **What does it cost to enter the 13x21.5x1 air filter niche?**
- Listings span $26.55–$60.18; the average listing price is $41.77 (sweet spot $15–$100). The average incumbent carries 14,247 reviews — the moat a new listing must climb.
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