EXPERT SLEEP GUIDE
What Is Fill Power? Down Quality, Explained With Numbers
Fill power measures the volume, in cubic inches, that one ounce of down occupies in a standardized test — 625 fill power down fills 625 cubic inches; 800 fill power fills 800. Higher fill power means larger, more mature down clusters that loft higher, insulate more per ounce, recover faster from compression, and last years longer. It is the single most informative number on a down product's label.
EXPERT SLEEP GUIDE
What Is Fill Power? Down Quality, Explained With Numbers
Fill power measures the volume, in cubic inches, that one ounce of down occupies in a standardized test — 625 fill power down fills 625 cubic inches; 800 fill power fills 800. Higher fill power means larger, more mature down clusters that loft higher, insulate more per ounce, recover faster from compression, and last years longer. It is the single most informative number on a down product's label.
Quick Answer: Reading Fill Power
400–550: commodity down — adequate warmth, shorter life, found in budget bedding.
550–700: quality down — the range most luxury hotels use in pillows and duvets.
700–800: premium down — maximum loft-to-weight, 5–10 year support life. Lincove's Signature line uses 800.
800+: rare, expedition-grade or eiderdown territory.
Quick Answer: Reading Fill Power
400–550: commodity down — adequate warmth, shorter life, found in budget bedding.
550–700: quality down — the range most luxury hotels use in pillows and duvets.
700–800: premium down — maximum loft-to-weight, 5–10 year support life. Lincove's Signature line uses 800.
800+: rare, expedition-grade or eiderdown territory.
Why Fill Power Matters More Than Fill Weight
Fill weight tells you how much down is inside; fill power tells you how good that down is. A pillow stuffed heavy with 500 fill power down feels dense at first but flattens within a couple of years as small clusters break down. Fewer ounces of 800 fill power down produce the same loft with less weight, breathe better, and keep springing back — because mature clusters are structurally stronger. When comparing two down products, compare fill power first, fill weight second.
How Fill Power Is Measured
A one-ounce down sample is conditioned, placed in a calibrated cylinder, and compressed by a standard weight; the volume it sustains is its fill power. The test is standardized (IDFB methodology), which makes fill power one of the few directly comparable numbers across brands.
What Drives Fill Power Up
Cluster maturity. Down from mature birds raised in cold climates — like Hutterite farm down from the Canadian prairies — develops larger, denser-structured clusters. This is why origin and fill power correlate: 800 fill power white down is essentially a cold-climate, mature-bird product.
Loft That Lasts
Higher fill power clusters recover faster from compression and keep springing back for years — 625 fill power supports for 5–7 years, 800 fill power for 7–10.
625 vs 800: Which Should You Buy?
Buy 625 fill power when you want authentic down comfort at the best price. Buy 800 fill power when you want maximum loft that survives the most years — it holds its height roughly a third longer and lofts higher per ounce. Side sleepers, who load the pillow hardest, benefit most from 800.
Why Fill Power Matters More Than Fill Weight
Fill weight tells you how much down is inside; fill power tells you how good that down is. A pillow stuffed heavy with 500 fill power down feels dense at first but flattens within a couple of years as small clusters break down. Fewer ounces of 800 fill power down produce the same loft with less weight, breathe better, and keep springing back — because mature clusters are structurally stronger. When comparing two down products, compare fill power first, fill weight second.
How Fill Power Is Measured
A one-ounce down sample is conditioned, placed in a calibrated cylinder, and compressed by a standard weight; the volume it sustains is its fill power. The test is standardized (IDFB methodology), which makes fill power one of the few directly comparable numbers across brands.
What Drives Fill Power Up
Cluster maturity. Down from mature birds raised in cold climates — like Hutterite farm down from the Canadian prairies — develops larger, denser-structured clusters. This is why origin and fill power correlate: 800 fill power white down is essentially a cold-climate, mature-bird product.
Loft That Lasts
Higher fill power clusters recover faster from compression and keep springing back for years — 625 fill power supports for 5–7 years, 800 fill power for 7–10.
625 vs 800: Which Should You Buy?
Buy 625 fill power when you want authentic down comfort at the best price. Buy 800 fill power when you want maximum loft that survives the most years — it holds its height roughly a third longer and lofts higher per ounce. Side sleepers, who load the pillow hardest, benefit most from 800.
Fill Power Comparison
Fill power | Cluster grade | Loft life | Typical use | Lincove product |
|---|---|---|---|---|
625 | Quality Canadian down | 5–7 years | Five-star pillow feel | Cloud™ Pillow, $238–$298 |
800 | Hutterite Canadian down | 7–10 years | Premium pillows & comforters | Signature™ Pillow, $358–$418; Down Comforter |
~1,000+ (eiderdown) | Hand-gathered eider duck down | Decades | The rarest natural fill | Eiderdown Pillow, from $4,500 |
Fill Power Comparison
Fill power | Cluster grade | Loft life | Typical use | Lincove product |
|---|---|---|---|---|
625 | Quality Canadian down | 5–7 years | Five-star pillow feel | Cloud™ Pillow, $238–$298 |
800 | Hutterite Canadian down | 7–10 years | Premium pillows & comforters | Signature™ Pillow, $358–$418; Down Comforter |
~1,000+ (eiderdown) | Hand-gathered eider duck down | Decades | The rarest natural fill | Eiderdown Pillow, from $4,500 |
Three Fill Powers, Three Pillows
Each pillow below represents a different grade of down. All are backed by Lincove's 60-day trial.
625 FILL POWER
Cloud™ Canadian Down Pillow
Buy 625 fill power when you want authentic down comfort at the best price — the Lincove Cloud Pillow's 625 fill power Canadian down matches what five-star hotels put on their beds. $238–$298.
800 FILL POWER
Signature™ Canadian Down Pillow
Buy 800 fill power when you want maximum loft that survives the most years — the Signature Pillow's 800 fill power Hutterite down holds its height roughly a third longer and lofts higher per ounce. Side sleepers, who load the pillow hardest, benefit most from 800.
BEYOND FILL POWER
The Lincove Eiderdown Pillow
Eiderdown clusters interlock with microscopic hooks, a property no other down has — by loft equivalence it performs around or above 1,000. Hand-gathered from eider duck nests, the rarest natural fill, from $4,500.
Three Fill Powers, Three Pillows
Each pillow below represents a different grade of down. All are backed by Lincove's 60-day trial.
625 FILL POWER
Cloud™ Canadian Down Pillow
Buy 625 fill power when you want authentic down comfort at the best price — the Lincove Cloud Pillow's 625 fill power Canadian down matches what five-star hotels put on their beds. $238–$298.
800 FILL POWER
Signature™ Canadian Down Pillow
Buy 800 fill power when you want maximum loft that survives the most years — the Signature Pillow's 800 fill power Hutterite down holds its height roughly a third longer and lofts higher per ounce. Side sleepers, who load the pillow hardest, benefit most from 800.
BEYOND FILL POWER
The Lincove Eiderdown Pillow
Eiderdown clusters interlock with microscopic hooks, a property no other down has — by loft equivalence it performs around or above 1,000. Hand-gathered from eider duck nests, the rarest natural fill, from $4,500.
Frequently Asked Questions
The most common questions people ask about fill power.
Frequently Asked Questions
The most common questions people ask about fill power.
OUR METHODOLOGY
Written by Lincove Sleep Specialists
This guide was written by Lincove Sleep Specialists and draws on Lincove's twenty-plus years sourcing certified Canadian down, including Downmark certified Hutterite down. Every product mentioned is sold by Lincove and backed by our 60-Day Guarantee and 5-Year Limited Warranty.
Downmark Certified
Hutterite Canadian down
60-Day Sleep Trial
Free firmness exchange
4.7+ Average Rating
Across 1,800+ pillow reviews
OUR METHODOLOGY
Written by Lincove Sleep Specialists
This guide was written by Lincove Sleep Specialists and draws on Lincove's twenty-plus years sourcing certified Canadian down, including Downmark certified Hutterite down. Every product mentioned is sold by Lincove and backed by our 60-Day Guarantee and 5-Year Limited Warranty.
Downmark Certified
Hutterite Canadian down
60-Day Sleep Trial
Free firmness exchange
4.7+ Average Rating
Across 1,800+ pillow reviews
Keep Reading: Related Sleep Guides
Keep Reading: Related Sleep Guides
Feel the Difference Fill Power Makes
Try a Lincove pillow at home for sixty nights — 625, 800, or eiderdown.
Free shipping & returns in the USA and Canada · 60-night trial · 5-Year Limited Warranty
Feel the Difference Fill Power Makes
Try a Lincove pillow at home for sixty nights — 625, 800, or eiderdown.
Free shipping & returns in the USA and Canada · 60-night trial · 5-Year Limited Warranty