Quick Answer: Coil gauge measures wire thickness: lower numbers mean thicker, firmer wire. Quality mattress coils run from 12.5 (very firm) to 15 (softer/lighter). In-store, look for gauge 13-14, individually wrapped (pocketed) coils, and a count above 1,000 for a queen. Our Restonic ComfortCare Queen has 1,222 pocketed coils at 14.5 gauge.
In This Guide
Reading Time: 7 minutes
Most people shopping for a mattress focus on how it feels when they lie on it for 90 seconds in a showroom. That is a reasonable starting point, but it does not tell you how the mattress will feel three years from now. The coil system underneath is a much better predictor of long-term durability.
You do not need to become an engineer to make a smart choice. You need to know a handful of numbers and a few questions to ask. This checklist gives you both.
What Is Coil Gauge and Why Does It Matter?
Gauge is a wire measurement system where the number works backwards from what you might expect: lower gauge = thicker wire = firmer and more durable coil. Higher gauge = thinner wire = softer and more susceptible to compression over time.
Here is a practical reference:
Coil Gauge Reference Chart
- 12.5 gauge: Very thick wire. Used in heavy-duty or firm orthopaedic models. Rare in consumer mattresses.
- 13 gauge: Firm and very durable. Good for heavier sleepers or those who want a firmer feel that holds up long-term.
- 13.5-14 gauge: The most common range in mid-grade to quality innersprings. Balances support and comfort. Often the best value zone.
- 14.5 gauge: Lighter wire, slightly softer feel. Fine in pocketed coils with high count, like our Restonic ComfortCare (1,222 coils at 14.5 gauge).
- 15 gauge: Thin wire. Tends to soften faster. Acceptable in a top comfort layer but not ideal as the primary support system.
- 15.5-16 gauge: Budget territory. These coils compress and fatigue relatively quickly under sustained body weight.
Gauge matters because a coil that is too thin for the sleeper's weight compresses over time without fully recovering. That gradual compression is what creates the body impression you feel as the mattress ages. It also affects edge support: thin-gauge coils at the perimeter give you that "rolling off the edge" feeling within a year or two.
Wire Gauge and Durability Research
Research on mattress longevity consistently shows that coil gauge interacts with body weight to determine fatigue rate. A study by Jacobson et al. (2008) in the Journal of Chiropractic Medicine found that participants who replaced old innerspring mattresses experienced measurable reductions in back pain, with the difference attributed primarily to loss of support in aged coil systems. The steel wire diameter determines how many compression cycles a coil can withstand before permanent set occurs, which is why manufacturers rate coils by gauge alongside coil count.
Coil Count: What Numbers Actually Mean
Coil count gets marketed heavily because bigger numbers sound impressive. The reality is more nuanced.
For a standard queen mattress, here is a useful benchmark:
- Under 600 coils: Budget range. Fine for occasional use (guest room), not ideal for nightly sleep.
- 600-800 coils: Entry-level. Acceptable for lighter sleepers or shorter ownership.
- 800-1,000 coils: Mid-range. Reasonable support, moderate longevity.
- 1,000-1,400 coils: Quality range. Better pressure distribution and reduced motion transfer in pocketed systems.
- 1,400+ coils: Premium. Diminishing returns beyond this unless coil diameter is very small (micro-coils).
The catch: coil count only means something in context of coil type and gauge. A mattress with 2,000 thin-gauge Bonnell coils will underperform a mattress with 1,000 quality-gauge pocketed coils. Always ask both numbers together.
Coil Count vs. Coil Quality
Manufacturers sometimes inflate coil counts by using micro-coils in a thin comfort layer on top of a main coil system. A mattress advertised as "2,000 coils" may have 800 main support coils and 1,200 tiny comfort coils sewn into the top panel. Ask specifically: how many coils are in the main support core? That number is what predicts longevity.
Coil Types to Know Before You Walk In
There are four main coil types you will encounter. Knowing the difference helps you evaluate what you are lying on.
The Four Main Coil Types
- Bonnell coils (hourglass shape, connected): The oldest design. Steel coils tied together with a wire grid (helical lacing). Affordable, durable, but the connected design transfers motion across the mattress. You feel your partner move. Common in budget to mid-range mattresses.
- Offset coils (hourglass with flat top/bottom): Similar to Bonnell but with a hinge-like flat section that allows the coil to contour slightly better. Better conforming than Bonnell, still connected.
- Pocketed coils (individually wrapped): Each coil sits in its own fabric sleeve. They compress independently, which dramatically reduces motion transfer. The gold standard for couples. Higher cost to manufacture but often more durable because they flex without pulling on neighbouring coils.
- Continuous coils (one wire forms many coils): A single wire snakes back and forth to form rows of coils. Very durable because there are no weak points at individual coil connections. Less conforming than pocketed. Common in higher-firmness models.
For most people shopping at Mattress Miracle, the practical choice comes down to: pocketed coils if you sleep with a partner (motion isolation is worth it), Bonnell or offset if you are buying a single or are firmly budget-constrained and sleep alone.
Your In-Store Checklist: 7 Questions to Ask
When you are in the showroom, these seven questions will give you what you need to compare honestly:
The 7 Questions to Ask In-Store
Question 1: What is the coil gauge?
You want a number, not a description like "firm" or "heavy-duty." The gauge tells you the wire thickness. For a queen with nightly use by an average adult, you want 13.5-14.5 gauge in the main coil core.
Question 2: Are the coils individually pocketed?
If the answer is yes, ask if that applies to the main support core or only a comfort micro-coil layer on top. You want pocketed coils in the support core for best motion isolation and longevity.
Question 3: How many coils in the support core (queen)?
Get the specific number for the queen size. Over 1,000 pocketed coils for a queen is a solid benchmark. If the salesperson can only give you total coil count including comfort layers, that number is less useful on its own.
Question 4: Is there zoned support?
Some pocketed coil systems use different gauge coils in different zones, typically firmer under the lumbar and softer under the shoulders. This can be worth paying for, especially if you are a side sleeper or have lower back concerns. Ask where the zones are and how many there are.
Question 5: What is the edge support design?
Ask specifically about edge coils. Some mattresses use the same coil throughout; better models use a reinforced perimeter with heavier-gauge coils or a foam rail around the edges. Sit on the edge: if it compresses dramatically under your weight, that perimeter will fail faster than the centre.
Question 6: What is the warranty threshold for coil failure?
Most Canadian mattress warranties define a coil defect as a broken or protruding coil. Ask what the warranty covers and for how long. Some warranties are 10 years, others 20 or 25, but read the fine print: many prorate significantly after year 3-5, meaning your claim pays a fraction of replacement cost.
Question 7: Is this mattress Canadian-made?
This matters for warranty service and parts sourcing. A Canadian-made mattress can often be serviced locally if a component fails. Our Sleep In collection is made in Canada. Our Restonic line is manufactured under Canadian licensing with Canadian quality standards.
What Brad Checks When He Evaluates a Coil System
Brad, our senior consultant at Mattress Miracle, has been fitting mattresses to Brantford families since the 1990s. When he evaluates a coil system, he focuses on three things: gauge, whether the coils are pocketed, and the edge design. "The middle of the mattress usually holds up," he says. "Where cheap innersprings fail is the perimeter. Within two years, you are sleeping in a bowl. Test that edge before you commit."
What to Watch Out For
A few common marketing tactics to recognise:
- "Individually wrapped" applied to micro-coils only: Some mattresses with Bonnell main cores add a thin pocketed micro-coil comfort layer and advertise "individually wrapped coils." The motion transfer you feel comes from the main core, not the top layer.
- Coil count inflation: A queen advertised as "3,000 coils" almost certainly includes both a main coil layer and a micro-coil comfort layer. Ask them to separate the numbers.
- Proprietary gauge names: Some brands invent names like "tempered TerraCoil" or "PowerEdge wire" that obscure the actual gauge. Push for the numerical gauge designation.
- No spec sheet available: A quality manufacturer should have a spec sheet for each model that lists coil count, coil type, gauge, and construction layers. If the salesperson cannot produce one, that is a signal.
For reference, here is what Mattress Miracle discloses about our Restonic innerspring line:
Restonic Coil Specs (Current Models)
- ComfortCare Queen ($1,125): 1,222 individually pocketed coils, 14.5 gauge. Best everyday value model.
- ComfortCare King ($1,455): 1,440 pocketed coils, 14.5 gauge. Highest coil count in the Restonic line.
- Revive Reflections ET Queen ($1,395): 1,200 pocketed coils, flippable dual-sided construction.
- Luxury Silk and Wool Queen ($1,395): 884 zoned pocketed coils. The zoned design here matters: different firmness zones under different body regions, using natural fibre comfort layers above.
- Revive Tiffany Rose/Jasmine Queen ($1,995): 1,188 pocketed coils, Talalay Copper Latex comfort layer.
- Revive St Charles/Elizabeth Queen ($2,150): 1,188 pocketed coils, 15-inch flagship build with substantial comfort layer depth.
If you want to compare an innerspring to a foam or hybrid option, our article on why foam goes soft explains how foam comfort layers interact with coil systems over time. For anyone coming in after a warranty issue, see our guide on how to measure mattress sag for a warranty claim.
You can also browse our current mattress collection online, but we strongly recommend coming in to check gauge and feel in person. The spec sheet tells you what the mattress is made of; lying on it tells you if it fits your body.
Frequently Asked Questions
Is a lower coil gauge always better?
Lower gauge means thicker, firmer wire, which is generally more durable for heavier sleepers or those wanting a firmer feel. But very low gauge (12.5 or 13) in a mattress marketed as "soft" just means the comfort layers are doing all the work, which can be fine. Match gauge to your weight and preferred firmness rather than chasing the lowest number automatically.
What coil count is good for a queen mattress?
For a queen with pocketed coils in the main support core, 1,000-1,400 is a solid quality range. Below 800 pocketed coils in a queen is acceptable for lighter sleepers or guest rooms. Coil count matters less than coil type and gauge: 1,200 well-made pocketed coils outperform 2,000 thin-gauge Bonnell coils in most real-world conditions.
Do pocketed coils last longer than Bonnell coils?
Usually, yes, for two reasons. Pocketed coils compress independently, so they do not pull on neighbouring coils when stressed. This reduces lateral fatigue over time. They also tend to be used in mid-to-upper-grade mattresses where overall construction quality is higher. That said, a well-made Bonnell coil mattress with reinforced perimeter can outlast a cheaply constructed pocketed model.
Can I feel the difference between coil gauges when I lie on a mattress?
Directly, no. The comfort layers between you and the coils absorb most of the difference in feel. What you feel is the interaction of comfort layer firmness and coil response combined. The gauge difference becomes apparent over years of use: thinner-gauge coils lose their "springback" and create body impressions sooner. This is why it pays to check gauge even when a mattress feels the same as another in the showroom.
Does Mattress Miracle in Brantford disclose coil specs for all models?
Yes. We can provide coil count, coil type, and gauge for all innerspring and hybrid mattresses in our showroom. If you are comparing two models side by side, ask Brad or Talia to pull the spec sheets and they will walk you through the numbers. We would rather you make an informed choice than sell you something that disappoints in two years.
Sources
- Jacobson, B.H., Boolani, A., & Smith, D.B. (2008). Changes in back pain, sleep quality, and perceived stress after introduction of new bedding systems. Journal of Chiropractic Medicine, 8(1), 1-8. doi.org/10.1016/j.jcm.2008.09.002
- Jacobson, B.H., Wallace, T.J., Smith, D.B., & Kolb, T. (2008). Grouped comparisons of sleep quality for new and personal bedding systems. Applied Ergonomics, 39(2), 247-254. doi.org/10.1016/j.apergo.2007.04.002
- National Institutes of Standards and Technology. (2020). ASTM F1566-20: Standard Test Methods for Evaluating the Durability of Innerspring Mattress and/or Foundation/Box Springs. ASTM International. astm.org/f1566-20.html
- Gordon, S.J., Grimmer-Somers, K., & Trott, P. (2009). Pillow use: the behaviour of cervical stiffness, headache and scapular/arm pain. Journal of Pain Research, 2, 137-145. doi.org/10.2147/JPR.S5108
- Defloor, T. (2000). The effect of position and mattress on interface pressure. Applied Nursing Research, 13(1), 2-11. doi.org/10.1016/S0897-1897(00)80013-0
- Consumer Product Safety Commission. (2016). Mattress Flammability Standard: 16 CFR Part 1633. U.S. CPSC. cpsc.gov
Related Reading
- Innerspring Insulator Layers: Why Your Coils Should Not Touch Your Foam
- Why Mattress Foam Goes Soft: Understanding IFD Decay
- How to Measure Mattress Sag for a Warranty Claim in Canada
- Mattress Warranty and Sagging Guide Canada
- Browse All Mattresses at Mattress Miracle
- Best Mattress for Night Shift Workers: Sleep Guide
- Why Does Mattress Foam Turn Yellow? Polyfoam Oxidation
- Burl Wood Bed Frames: What Mattress Depth and Type Works Best
- Art Deco Bedroom: Best Mattress for 1920s-Style Bed Frames
Visit Our Brantford Showroom
Mattress Miracle
441 1/2 West Street, Brantford
Phone: (519) 770-0001
Hours: Mon-Wed 10-6, Thu-Fri 10-7, Sat 10-5, Sun 12-4
Bring your checklist. Brad and Talia will pull the spec sheets on any model you are comparing. We have been helping Brantford families find the right mattress since 1987, and we are happy to talk coil counts for as long as you need.