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.

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.

Conversion

Incredible15.9%

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

Great2.0%

return rate — above 5% kills the launch gate

Growth

Good+27.4%

90-day search growth — must beat 0% to launch

Review moat

Okay3,366

avg incumbent reviews — the moat a new listing must climb

Market size

Okay$126K

$126K/yr · 19K searches

Quality gap

Bad4.7★

avg incumbent rating — lower means beatable quality

Competition

Bad100%

top-5 click share — a locked-up shelf

Brand share

Bad100%

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

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

Top-5 brand share

100%

Top 20: 100%

Top-5 click share

100%

Top 20: 100%

Open market

Aerostar57%
Filtrete39%
Filter King4%

Demand & seasonality

Weekly Amazon search volume, last 102 weeks — +27.4% search growth over the last 90 days.

Peak months: Jan, Feb, Nov · busiest ÷ quietest = 2.4×

Open Trend

Top 16.5 x 21.5 x1 air filter search terms

16.5x21.5x1 air filter12K/yr +23.2%7.9% conv.
16.5 x 21.5 x 1 air filter4K/yr +35.0%8.3% conv.
16 1/2 x 21 1/2 x 1 air filter3K/yr +37.1%6.7% conv.

All 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.

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

Aerostar 16.5x21.5x1 MERV 8 - 6 Count - High Efficiency Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Lint Mold & Allergy-Causing Pollen

Aerostar$37.934.6★2,445 rev

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$38.624.7★6,265 rev

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$33.334.7★4,106 rev

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$40.324.7★1,569 rev

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$54.914.6★2,445 rev

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$38.626,265 rev

2y ago

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$40.321,569 rev

3y ago

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$33.334,106 rev

6y ago

Aerostar 16.5x21.5x1 MERV 8 - 6 Count - High Efficiency Pleated HVAC Furnace & Air Conditioner Filters - Removes Dust Lint Mold & Allergy-Causing Pollen

Aerostar$37.932,445 rev

10y ago

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$54.912,445 rev

10y ago

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-Overall36%

“Good quality”

Filtration19%

“Really good filters”

Advertised Vs Actual Product8%

“As advertised”

Size-Overall8%

“They fit nicely, dont flop around. horizontal install., and do a good job catching small and large particles”

Value For Money7%

“Perfect and Great price”

Functionality-Overall4%

“do a good job catching small and large particles”

Ease Of Use4%

“Easy to use”

Storage Capacity4%

“love having a bulk supply”

Assembly/Installation3%

“So easy to install”

Color3%

“Love the color white also”

What buyers complain about

Quality-Overall22%

“very cheap”

Filtration11%

“This filter is incredibly cheap and flimsy”

Size-Overall11%

“Was given the wrong size”

Strength11%

“Flimsy, very cheap”

Design-Overall11%

“Definite design flaw”

Assembly/Installation11%

“when it literally crumbles in your hand trying to install it, its garbage”

Top return reasons

Size-Overall63%

Filtration21%

Compatibility-Overall8%

Defective Material/Parts2%

Value For Money1%

Quality-Overall1%

Advertised Vs Actual Product1%

Certifications1%

Thickness1%

Thin0%

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.