Sleep Firm Ultra Mattress

Sleep Firm Ultra Mattress Review

The Sleep Firm Ultra Mattress is the mid-range model in the Sleep Firm lineup, sitting above the popular entry-level Sleep Firm Mattress.

It’s designed for sleepers who genuinely prefer an exceptionally firm feel and is arguably one of the firmest mattresses-in-a-box available in Australia.

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✏️ Product summary

• Innerspring mattress
• Extra-firm feel
• Mattress in a box
• Australian made
• 150 night trial period
• Current best price is $1,519.24 (queen)
• Click SHOP NOW and use code BBEXTRA5 to unlock this price

Purchase and delivery

How do I order the Sleep Firm Ultra Mattress?

The Sleep Firm Ultra Mattress can be ordered directly through the Sleep Firm website.

Delivery is free to eligible metropolitan and inner-regional areas, provided your location is serviced by Sleep Firm’s delivery partners. Once your order is placed, the mattress is dispatched from the company’s Melbourne warehouse, and delivery times generally follow the schedule below:

• Melbourne Metro: within 5 business days
• Sydney, Brisbane, Adelaide & Canberra Metro: within 14 business days
• All other areas: within 21 business days

Business days refer to Monday–Friday and exclude weekends and public holidays. In some cases, delivery timeframes may be longer depending on your location.

For Melbourne Metro customers, SleepFirm offers an optional Premium Delivery Service for an additional $89. This includes carrying the mattress inside and setting it up in your chosen room. The room must be empty and ready for installation, as this service does not include the removal or disposal of old bedding.

If you place your order before 2 pm AEDT and live in selected Melbourne suburbs, you may be eligible for next-business-day delivery.

Our mattress arrived in typical “mattress-in-a-box” packaging. The box was in good condition, easy to manage, and we recommend having two people on hand to carry and unpack it. Unboxing is simple: just cut the outer plastic wrap and allow the mattress to expand.

As with most boxed mattresses, expect a fair amount of packaging, so it’s worth planning some bin space for cardboard and plastic.

Aesthetics and Presentation

What does it look like in real life?

The SleepFirm Ultra Mattress presents with a sleek, modern look that suits contemporary bedroom settings.

Its deep charcoal quilting gives it a bold, refined appearance, and the uniform stitching pattern adds a touch of sophistication. At 28 cm high, it has a solid, substantial profile without appearing overly bulky.

In a styled room, the mattress blends seamlessly with minimalist decor – neutral tones, clean lines, and simple furnishings.

The overall presentation feels calm and uncluttered, making the SleepFirm Ultra an attractive centrepiece that complements a wide range of bedroom interiors.

Mattress construction

What’s inside the Sleep Firm Ultra Mattress?

The SleepFirm Ultra Mattress is engineered for maximum firmness and long-term support.

Its construction combines ultra-dense foams with a reinforced 5-zone spring system, creating one of the firmest mattress-in-a-box options available in Australia.

1. Bekaert Deslee ‘Adaptive’ Fabric Cover

The top cover is made from advanced Bekaert Deslee ‘Adaptive’ fabric – a smooth, breathable textile designed to wick away heat and moisture. It feels soft and cool to the touch and helps maintain a comfortable sleep temperature throughout the night.

2. Double Layer of Boomerang Foam

This mattress features two layers of Boomerang Foam, a premium-density foam engineered to spring back into shape quickly. Its open-cell structure promotes ventilation, helping the mattress stay cooler and more responsive.

The dual layering increases firmness and durability, contributing to the mattress’s ultra-firm feel.

3. S+ Pro 5-Zone Pocket Spring System

The mattress’s core is the S+ Pro 5-Zone Pocket Spring System, designed for precision support and long-term performance.

Each spring is individually encased, allowing it to respond independently to pressure and movement. With up to 1,326 springs in a King size, the system offers excellent spinal alignment and helps minimise partner disturbance.

The springs are made with medical-grade fabric and tested to be up to 42% stronger than standard pocket springs, reinforcing the mattress’s firm, stable feel from edge to edge.

4. Foam Box Edge

A high-density foam encasement surrounds the spring unit to strengthen the perimeter and prevent roll-off. This sturdy edge design ensures the mattress maintains consistent firmness and support across the full sleeping surface.

Comfort and support

What’s it like to sleep on the Sleep Firm Ultra Mattress?

The top surface of the SleepFirm Ultra feels smooth, breathable, and well-finished. The grey cover fabric has a clean, modern look and a high-quality texture that closely resembles the original SleepFirm Mattress, helping maintain the brand’s signature edgy aesthetic.

As expected, this mattress is extraordinarily firm. The double layer of Boomerang Foam, combined with the heavy-duty spring system, creates an ultra-supportive sleeping surface.

Despite its firmness, there is a slight responsiveness in the top layers that prevents the mattress from feeling rock hard. The firmness is immediate and unmistakable – this model is built specifically for sleepers who genuinely prefer an ultra-firm profile.

All of our expert reviewers agreed on the firmness level, arriving at a rating of 9.5 / 10 (with 10 being the firmest). We classify the Sleep Firm Ultra as extra firm.

Firmness rating

This level of firmness is best suited to back sleepers or anyone who genuinely prefers an extremely firm, highly supportive mattress. The spring system feels strong and stable, providing excellent spinal support for most body types – as long as the sleeper is comfortable with an ultra-firm feel.

Please note that our firmness ratings are only a guide and may differ from those provided by individual companies. Mattress firmness can also vary depending on the type of bed base used.

We tested the Sleep Firm Ultra Mattress on the Porto Bed Base, a high-quality platform with rigid slats.

The Sleep Firm Ultra responds efficiently to normal movement, and we rated its level of responsiveness as optimal. In practical terms, shifting positions – or engaging in more active movements – should feel easy and require very little extra effort.

Responsiveness

Please note that our responsiveness scales are also just a guide, and preferred responsiveness will vary between individuals. It’s worth noting that innerspring mattresses are generally more responsive than foam mattresses.

The finer details

The Sleep Firm Ultra Mattress is well built, with a level of construction quality that in some ways exceeds its price point. At 28 cm high, it sits comfortably within the standard height range for an innerspring mattress, and most fitted sheets will fit without issue.

Motion isolation is very good – the combination of dense foams and the pocket spring system helps to reduce partner disturbance, although the level of movement felt will naturally depend on sleeper weight and the mattress size.

When it comes to motion transfer on a mattress, larger sizes such as a king size tend to involve less partner disturbance.

Edge support is another highlight. The foam box encasement creates a stable, supportive perimeter, allowing sleepers to lie or sit near the edge without feeling unsteady or at risk of rolling off. This reinforced border also contributes to the mattress’ overall structural durability.

The side handles are well-constructed and made from a durable mesh-style material. Positioned vertically, they provide ample grip and make rotating or repositioning the mattress far easier – we commend Sleep Firm for including these.

Despite its firmness, there is a slight responsiveness in the top layers that prevents the mattress from feeling rock hard.

We did not notice any concerning heat retention during testing. The open-cell foams, breathable fabrics, and inherently very firm profile all help prevent excessive warmth for most sleepers.

Naturally, sleep temperature will still vary depending on bedding, room conditions, and individual body heat.

The Sleep Firm Ultra Mattress is also GECA-certified and Sensitive Choice approved, reinforcing its environmental credentials and suitability for allergy-sensitive sleepers.

Other details

Product weight of each mattress size (approximately):

• King Mattress: 44kg
• Queen Mattress: 37kg
• Double Mattress: 30kg
• King Single Mattress: 26.5kg
• Single Mattress: 21kg

Country of Origin

Manufactured in Melbourne, Australia.

Bed base compatibility

What type of bed base should I use?

As with most mattresses, we recommend the Sleep Firm Ultra Mattress to be used on a bed base with flat panel slats such as the Koala Paddington Bed Base.

A bed base with solid slats such as the Porto Bed Base would also be very suitable.

Koala Paddington Bed Base

We would advise against using a bed base with flexible (posture) slats as this type of base may not provide adequate support. Ultimately, the use of an unsupportive mattress foundation will void the mattress warranty.

We don’t recommend the Sleep Firm Ultra Mattress be used with an adjustable (electric) bed base. as this may cause damage to the mattress components. Here is our full list of mattresses that are compatible with an adjustable bed base.

It’s worth noting here that mattress firmness, performance, and durability will vary with different bed bases.

Trial period and warranty

What happens if I don’t like it?

The Sleep Firm Ultra Mattress includes a 150-day trial period, which is in line with many online mattress brands. This gives you plenty of time to test the mattress in your own home and decide whether the ultra-firm feel suits your needs.

If you’re not satisfied within the trial window, you can return the mattress for a refund, provided it meets the return conditions set by SleepFirm.

The mattress is also backed by a 15-year warranty, covering faults in materials and workmanship. This warranty length is stronger than what many similarly priced competitors offer, adding extra peace of mind and reinforcing the product’s overall value.

Available sizes

What size options are available?

The Sleep Firm Ultra Mattress is available in 5 sizes (king, queen, double, king single, and single size) so it should accommodate most sleeping arrangements.

The graphic below includes all of Australia’s standard bed (mattress) sizes in 2025. Again please note that the Sleep Firm Ultra Mattress is available in 5 of these sizes.

Prices

How much does the Sleep Firm Ultra Mattress cost?

Here are the retail prices of the Sleep Firm Ultra Mattress.

Retail Prices

• King Mattress: $2,399
• Queen Mattress: $1,999
• Double Mattress: $1,899
• King Single Mattress: $1,799
• Single Mattress: $1,499

Did you know?

Award winning product

The entry-level (original) Sleep Firm Mattress is a multiple award winner, having claimed Australia’s Best Firm Feel Mattress in a Box for three consecutive years. It’s a standout performer for those seeking a high quality firm mattress at an affordable price.

Final verdict

Is the Sleep Firm Ultra Mattress right for you?

The Sleep Firm Ultra Mattress delivers an impressive overall package, combining a robust, highly responsive spring system with quality comfort materials. It offers very good value and stands out as one of the top options in the extra-firm mattress category.

Bedbuyer’s rating:  4.6 / 5

Here are our ratings for each category:

Did you know? Bedbuyer recently announced Australia’s Top 12 Mattress in a Box in 2025.

If you have any questions about this mattress, leave a comment below and we’ll respond shortly!