Double Mattresses

What size is a UK double mattress?

All of our UK double mattresses measure 135cm x 190cm (4'6" x 6'3") - the ideal size for couples, guest rooms, or solo sleepers who want more space.

Will a double mattress fit my bed?

If your bed frame fits a 135cm x 190cm mattress, any double mattress from our range will fit perfectly.

Whether you're shopping for a mattress for a double bed or looking for a double-size mattress, we’ve got options in stock and ready to ship.

How deep should my double mattress be?

Most of our double mattresses range from 20cm to 30cm deep, giving you plenty of choice to suit your current bed frame and bedding. Whether you prefer a low-profile style or extra-deep luxury, we’ve got a double mattress to suit your needs.

Why buy your double mattress from MattressOnline?

Buying a mattress online should be stress-free. Here's what you get with MattressOnline.

• 100 Nights to be sure: Sleep on your new double mattress for 100 nights. If it isn't right for you, our 100-Night Sleep Trial has you covered.
• Real expert help: Our Sleep Experts, led by our Head of Sleep Science, answer the questions a spec description can't.
• Awarded products, not just claims: We stock Which? Best Buy and Good Housekeeping award-winning mattresses from over 40 brands. We're also six-time NBF Bed Retailer of the Year, so you can trust us with your sleep.
• Over 20 years, 72,000+ reviews: We've sold mattresses since 2003 and hold a 4.7 out of 5 Trustpilot rating.
• Delivered fast, hassle-free: Order by 4pm for free next day delivery to most of the UK. Add mattress recycling at checkout and we'll take your old one away. No stress.

Expert Tips: How firm should my double mattress be?

Our double mattresses come in every firmness level to suit your sleep style. Here’s what our Head of Sleep Science recommends:

• Soft-medium - gentle cushioning
• Medium - balanced support for most sleepers
• Medium-firm - ideal for couples with different comfort needs
• Firm - great for back sleepers
• Extra firm - our most supportive feel

Not sure what firmness is right for you? Try our 100-Night Comfort Trial risk-free.

How much do double mattresses cost?

Double mattress prices vary based on brand and materials, but our Sleep Experts have selected options for every budget:

• Budget: from £200 - affordable comfort you can rely on, every night
• Mid range: £300-£400 - enhanced support and added features for long-term comfort
• Premium: £600-£3000+ - luxury craftsmanship from the UK’s top mattress brands

Our Sleep Experts work directly with trusted names like Silentnight, Sealy, and Harrison Spinks to offer the best quality double mattresses at every price point.

You'll find our best price double mattresses in the latest double mattress sale - all with free next day delivery.

Can you take away my old double mattress?

Yes, when you order a double mattress from MattressOnline, we can take your old one away for just £35.

Our non-profit recycling service ensures every part of your old mattress is responsibly processed - giving you peace of mind with your purchase.