pd ruler
Worth a lookShows beatable incumbent ratings (3.9★), but soft demand (-9.6% this quarter) keeps it on the watch list.
Quality gap
Incredible3.9★avg incumbent rating — lower means beatable quality
Conversion
Great11.4%search→purchase rate — share of searches ending in a sale
Review moat
Great144.93avg incumbent reviews — the moat a new listing must climb
Avg price
Great$16.92avg listing price — sweet spot $15–$100
Price range
Great$4.99–$116.84cheapest to priciest tracked listing — scored on the share inside $15–$100
Returns
Good2.7%return rate — above 5% kills the launch gate
Brand share
Good73%top-5 brand share — brands hold most of the demand
Market size
Okay$121K$121K/yr · 63K searches
Competition
Okay68%top-5 click share — leaders hold, buyers still browse
Growth
Bad-9.6%90-day search growth — must beat 0% to launch
According to Flapen's Amazon United States niche tracking, pd ruler is a $121K/yr Amazon United States market (63K searches/yr). The top 5 brands hold 73% of demand. Verdict: Worth a look — 54/100.
Data updated Jul 28, 2026 · scored weekly · How we score niches
pd ruler market data
- Units sold / yr
- 6K–8K
- avg 500–750/product
- Revenue / yr
- $102K–$135K
- units × avg price
- Conversion rate
- 11.4%
- Avg BSR
- #464
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 100%
- Out of stock
- 10.3%
- Avg brand age
- 59 months
- Avg seller age
- 192 days
Competition & brand share
The top 5 products take 68% of clicks — established leaders, but buyers still shop beyond them.Brands
14 rising
Sellers
17
Top-5 brand share
73%
Top 20: 100%
Top-5 click share
68%
Top 20: 100%
Open market
23%
- Ezyaid40%
- Asofelk11%
- Ultrassist10%
- VV LIINNCXM7%
- Uoeo5%
- Jxiwfvl4%
Demand & seasonality
Weekly Amazon search volume, last 69 weeks — -9.6% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.5×
Top pd ruler search terms
- pd ruler for eyeglasses19K/yr
- pupillary distance ruler13K/yr
- pd ruler10K/yr
- pd measurement tool for eyes9K/yr
- pupillary distance measurement tool6K/yr
- pupil distance measuring tool6K/yr
Top pd ruler 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.
All 15 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Ezyaid PD Ruler with Instruction Manual - Pupillary Distance Ruler for Pupil Distance Measuring PD Measurement Tool for Prescription Eyeglasses Include Eye Care Tips
Ezyaid$6.994.4★480 rev
1PCS Plastic PD Ruler for Eyeglasses Measure Optical Vernier PD Ruler
Asofelk$6.043.3★31 rev
Ultrassist Pupillary Distance Ruler for Eyeglasses
Ultrassist$5.974.1★484 rev
PD Ruler for Eyeglasses Pupillary Distance Ruler PD Measurement Tool 1 Pack
VV LIINNCXM$5.924.5★2 rev
Ezyaid PD Ruler for Eyeglasses with Pupillary Distance Guide
Ezyaid$5.944.4★165 rev
Newest
by launch date
Pupillometers for Measuring Pupillary Distance with Electronic Instruction Manual Transparent Pupillary Distance Ruler for Pupil Measuring Essential Tool for Single PD or Dual PD Measurement
EupHHonycs$5.120 rev
4 Pcs PD Ruler for Eyeglasses Pupillary Distance Ruler Ideal for Ordering Glasses Online (White)
Thrymme$6.572 rev
2 Pcs PD Ruler for Eyeglasses Pupillary Distance Ruler PD Measurement Tool for Ordering Glasses Online
Skrfren$5.620 rev
4 Pcs PD Ruler for Eyeglasses Pupillary Distance Measurement Tool White PVC Pupilometer Ruler for Ordering Glasses Online Eye Care Accessory
LUSTRIB$4.991 rev
WJIAAA Plastic PD Ruler for Eyeglasses 2 Style Measure Optical Vernier PD Ruler Eye Ophthalmic Pupil Distance Measuring Tool Pupillary Distance Measurement Tool for Ordering Glasses Online
WJIAAA$6.323 rev
Trending
90-day click momentumPupillometers for Measuring Pupillary Distance with Electronic Instruction Manual Transparent Pupillary Distance Ruler for Pupil Measuring Essential Tool for Single PD or Dual PD Measurement
EupHHonycs$5.120.0★
WJIAAA Plastic PD Ruler for Eyeglasses 2 Style Measure Optical Vernier PD Ruler Eye Ophthalmic Pupil Distance Measuring Tool Pupillary Distance Measurement Tool for Ordering Glasses Online
WJIAAA$6.323.5★
2 Pcs PD Ruler for Eyeglasses Pupillary Distance Ruler PD Measurement Tool for Ordering Glasses Online
Skrfren$5.620.0★
4 Pcs PD Ruler for Eyeglasses Pupillary Distance Ruler Ideal for Ordering Glasses Online (White)
Thrymme$6.574.5★
4 Pcs PD Ruler for Eyeglasses Pupillary Distance Measurement Tool White PVC Pupilometer Ruler for Ordering Glasses Online Eye Care Accessory
LUSTRIB$4.994.0★
What buyers say about pd ruler
What buyers praise and complain about, mined from review topics.What buyers love
“As described”
“a very good value since you receive 4 of them”
“They are easy to use if you know how to use it”
“They are good quality”
“The materials feel durable”
“easy to follow instructions”
“Works no issues”
“like will be durable too”
“Functionally, it's perfect”
“Thrymme brand Pupillary Distance Ruler for Eyeglasses are flexible”
What buyers complain about
“No directions which can cause inaccurate measurements”
“Very difficult to use”
“The lines are nearly impossible to see when trying to measure”
“Not worth your money honestly”
“Questionable build quality”
“Dirty”
“stains on it I had to clean off”
Top return reasons
Common questions
- Is pd ruler profitable to sell on Amazon United States?
- The niche generates $121K/yr across 15 tracked products. 0 of 8 products launched in the last 360 days are still selling. 90-day search growth is -9.6%. Flapen's verdict: Worth a look (54/100).
- How competitive is the pd ruler niche?
- 14 brands and 17 sellers compete. The top 5 products take 68% of clicks and top 5 brands hold 73% of demand.
- What do buyers complain about in pd ruler?
- Top complaints mined from reviews: Instructions/User Manual/Troubleshooting, Ease Of Use, Measurement/Reading Accuracy. The return rate is 2.7%.
- When does demand for pd ruler peak?
- Demand is steady year-round — the busiest month runs 1.5× the quietest.
- What does it cost to enter the pd ruler niche?
- Listings span $4.99–$116.84; the average listing price is $16.92 (sweet spot $15–$100). The average incumbent carries 145 reviews — the moat a new listing must climb.