Prices verified Aug 4 · Always confirm at the retailer before buying.
Quick answer
For US shoppers comparing Simply 16x25x4 MERV 8 (6-Pack) with Filtrete 18x20x1 MERV 13 (2-Pack), the captured registry lists $75.21 and $45.99. Calculated from title-stated pack counts, that is $12.53 versus $23.00 per filter. The exact size labels differ, so neither should be treated as an automatic substitute. Filtrete has the higher captured rating at 4.8 versus 4.7; Simply has the larger captured review pool. MERV labels are recorded as title inputs, not health or filtration promises. Verify the exact HVAC slot, nominal and actual dimensions, thickness, airflow guidance, rating, delivered price, seller, and pack count before ordering.
Simply has the lower calculated cost per filter; Filtrete has the higher captured rating. The exact size labels differ, so verify HVAC fit before buying.
Mubboo Verdict
Best for most people
Simply 16x25x4 MERV 8 Air Filter (6-Pack)
Lower calculated cost per filter when the exact 16x25x4 system fit is verified.
Pick the Filtrete 18x20x1 MERV 13 Air Filter (2-Pack) instead if
- The exact 18x20x1 title matches your system.
- You prefer the higher captured marketplace rating.
- The lower upfront 2-pack price matters.
Simply 16x25x4 MERV 8 Air Filter (6-Pack) vs Filtrete 18x20x1 MERV 13 Air Filter (2-Pack), side by side
Simply 16x25x4 MERV 8 Air Filter (6-Pack)
Pros:
- Lower calculated cost per filter
- Larger title-stated 6-pack
- Captured rating and review count are captured
Cons (honest weight):
- Different 16x25x4 size label
- MERV label is not a universal performance recommendation
- Exact HVAC compatibility requires verification
Filtrete 18x20x1 MERV 13 Air Filter (2-Pack)
Pros:
- Higher captured marketplace rating
- Captured title provides a different 18x20x1 size label
- Lower upfront pack price
Cons (honest weight):
- Higher calculated cost per filter
- Smaller title-stated 2-pack
- Exact HVAC compatibility requires verification
Where each one wins
8 dimensions scored head-to-head. Simply 16x25x4 takes 3; Filtrete 18x20x1 takes 2.
| Dimension | Simply 16x25x4 MERV 8 Air Filter (6-Pack) | Filtrete 18x20x1 MERV 13 Air Filter (2-Pack) | Winner |
|---|---|---|---|
| Captured US priceFiltrete is $29.22 lower upfront in the captured registry snapshot. | $75.21 | $45.99 | Filtrete 18x20x1 |
| Price per filterCalculated from the captured pack prices and title-stated pack counts; pack contents and price can change. | $12.53 | $23.00 | Simply 16x25x4 |
| Exact size labelThese are different title-stated dimensions and should not be treated as interchangeable. | 16x25x4 | 18x20x1 | Tie |
| MERV title labelThe labels are recorded from the captured titles; confirm the HVAC manufacturer guidance before changing rating or thickness. | MERV 8 | MERV 13 | Tie |
| Pack countSimply has the larger title-stated pack count. | 6-pack | 2-pack | Simply 16x25x4 |
| Registry ratingFiltrete has the higher captured marketplace rating; this is not an HVAC performance test. | 4.7 / 5 | 4.8 / 5 | Filtrete 18x20x1 |
| Captured review poolSimply has the larger captured review pool; volume is not proof of fit or filtration performance. | 53,198 | 17,094 | Simply 16x25x4 |
| Fit and system compatibilityNeither filter should be selected from price or MERV label alone; verify dimensions, airflow guidance, and the exact HVAC system. | Verify exact slot | Verify exact slot | Tie |
| Overall | 3 wins | 2 wins | Simply 16x25x4 |
Start with the exact filter slot
For US shoppers, Simply is labeled 16x25x4 and Filtrete is labeled 18x20x1 in the captured registry titles. Those dimensions are different, so this is not a universal swap. Remove the live filter or check the HVAC manual and match the printed size before comparing price or MERV label.
Do not use the words MERV, 4-inch, or 1-inch as a substitute for system guidance. Verify the nominal and actual dimensions, airflow instructions, filter access, and the rating your HVAC manufacturer or technician recommends.
Price and pack math
Simply is listed at $75.21 for a 6-pack, or $12.53 per filter when the pack is divided evenly. Filtrete is listed at $45.99 for a 2-pack, or $23.00 per filter. The calculation uses captured registry prices and title-stated pack counts; it does not predict future prices or replacement intervals.
The lower calculated cost per filter only matters if the exact size, thickness, rating, and HVAC guidance match. A larger pack is not automatically better when a filter does not fit the return or cabinet.
MERV labels are comparison inputs, not health promises
The captured titles identify Simply as MERV 8 and Filtrete as MERV 13. This comparison records those labels without turning them into claims about allergy relief, asthma outcomes, smoke removal, bacteria capture, or indoor-air improvement.
A higher label may affect airflow or system suitability depending on the equipment. Check the HVAC documentation before changing rating or thickness, and stop if the exact model guidance conflicts with a marketplace listing.
Ratings and reviews
Simply is recorded at 4.7 stars from 53,198 captured reviews; Filtrete is recorded at 4.8 stars from 17,094. Filtrete has the higher rating, while Simply has the larger captured review pool.
These are marketplace signals, not controlled tests of fit, airflow, filtration, noise, energy use, service life, or health outcomes. Read recent reviews for the exact ASIN and size variation, but keep anecdotes separate from the registry facts.
Choosing between these two listings
Choose Simply when the 16x25x4 title matches your system and the lower calculated cost per filter matters. Choose Filtrete when the 18x20x1 title matches your system and the higher captured rating or lower upfront pack price matters.
Neither is the right choice if the dimensions, thickness, or rating do not match the system. Confirm the exact delivered price, seller, pack count, and return terms before ordering.
Alternatives and boundaries
Colorfil is a separate 20x25x1 MERV 8 four-pack. Kraftex is a portable-AC exhaust hose, not a replacement filter. They are useful only when the product type and exact equipment requirement match.
No independent test established filtration performance, airflow effect, replacement interval, allergy or asthma benefit, smoke removal, bacteria capture, durability, or HVAC safety. The recommendation is limited to captured US registry facts, calculated pack math, and exact title labels.
Which should you buy?
| Your situation | Pick | Why |
|---|---|---|
| Lower cost per filter | Simply 16x25x4 MERV 8 Air Filter (6-Pack) | Calculated cost is $12.53 per filter. |
| Lower initial spend | Filtrete 18x20x1 MERV 13 Air Filter (2-Pack) | Upfront pack price is $45.99. |
| Higher rating | Filtrete 18x20x1 MERV 13 Air Filter (2-Pack) | Filtrete has the higher captured rating. |
| 16x25x4 system | Simply 16x25x4 MERV 8 Air Filter (6-Pack) | The title label is 16x25x4; verify the exact system fit. |
| 18x20x1 system | Filtrete 18x20x1 MERV 13 Air Filter (2-Pack) | The title label is 18x20x1; verify the exact system fit. |
| 20x25x1 alternative | Simply 16x25x4 MERV 8 Air Filter (6-Pack) | Colorfil is the separate 20x25x1 alternative. |
Calculated cost is $12.53 per filter.
Upfront pack price is $45.99.
Filtrete has the higher captured rating.
The title label is 16x25x4; verify the exact system fit.
The title label is 18x20x1; verify the exact system fit.
Colorfil is the separate 20x25x1 alternative.
What if neither is right?
Colorfil 20x25x1 MERV 8 Air Filter (4-Pack)
$76.99
A four-pack with a 20x25x1 MERV 8 title label; verify the exact HVAC slot and live listing.
Kraftex Portable AC Exhaust Hose (5" Diameter, Anti-Clockwise)
$29.99
A separate portable-AC exhaust hose, not a substitute for either HVAC filter.
Frequently Asked Questions
Which is better, Simply or Filtrete?
Simply has the lower calculated cost per filter at $12.53; Filtrete has the higher captured rating at 4.8. The size labels differ, so the right choice is the one that matches your HVAC system.
Which air filter is cheaper per filter?
Simply calculates to $12.53 per filter from the captured 6-pack price; Filtrete calculates to $23.00 from the captured 2-pack price.
Are 16x25x4 and 18x20x1 interchangeable?
Do not assume so. They are different title-stated dimensions. Match the printed filter size and HVAC documentation before ordering.
Does MERV 13 guarantee better health results?
No conclusion was established. MERV labels are recorded from the captured titles; health, allergy, asthma, smoke, and airflow outcomes were not independently tested.
Which one has the higher rating?
Filtrete is recorded at 4.8 stars from 17,094 captured reviews; Simply at 4.7 stars from 53,198.
Did Mubboo test filter life or HVAC performance?
No. This comparison does not establish service life, airflow effect, filtration performance, noise, energy use, health outcomes, or system safety.
Primary sources: Price, rating, review count, stock, product title, and product image are drawn from captured US registry records for Simply, Filtrete, Colorfil, and Kraftex. The Simply and Filtrete records were last refreshed 2026-07-13; Colorfil was refreshed 2026-08-02; Kraftex was refreshed 2026-07-13. Recheck the live ASIN pages for price, stock, pack, and fit before buying. The titles support the dimensions, MERV labels, pack counts, and product types quoted here; they do not establish filtration performance, airflow, health outcomes, or compatibility with every HVAC system.
Who wrote this and where's the data from?
Author: Mubboo Editorial Team. Independent US-market consumer research using captured registry records and exact listing information. Last verified: 2026-08-04. No controlled filtration, airflow, lifespan, health, or HVAC-safety testing is claimed.