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Mattress Size Converter

Compare standard US and UK/EU mattress sizes in both inches and centimeters.

Result

Width
152 cm / 59.8 in
Length
203 cm / 79.9 in

Based on standard US and UK mattress dimensions. Exact sizes can vary by a centimeter or two between manufacturers.

About the Mattress Size

This calculator looks up the standard dimensions of a mattress size, US or UK/EU, and displays the width and length in both centimeters and inches. It's built for anyone comparing bedding, bed frames, or mattress protectors across countries that use different sizing names and units, such as matching a Queen mattress to its closest UK equivalent.

How It Works

You pick a mattress size from a dropdown covering six US sizes (Twin through California King) and four UK sizes (Single through Super King). The calculator looks up that size's fixed width and length in centimeters from a reference table, then converts both figures to inches by dividing by 2.54, so you see the dimensions in both units side by side.

Width and length are fixed lookup values per size; inches = centimeters / 2.54

Formula & Methodology

Each size has a hard-coded centimeter width and length pulled from standard mattress industry dimensions; for example a US Queen is stored as 152 cm by 203 cm and a UK King as 150 cm by 200 cm. Selecting a size retrieves that pair and divides each figure by 2.54 to produce the inch equivalent, so there's no rounding or interpolation involved, just a direct unit conversion of a fixed reference number.

Examples

US Queen Dimensions

Selecting Queen (US) returns a width of 152 cm (59.8 in) and a length of 203 cm (79.9 in), the standard US mattress size.

Comparing to a UK King

Selecting King (UK) instead shows 150 cm (59.1 in) wide by 200 cm (78.7 in) long, revealing it's nearly the same width as a US Queen but about 3 cm shorter.

Advantages

  • Covers both US and UK/EU naming conventions in a single lookup, avoiding confusion between region-specific size charts.
  • Displays results in both centimeters and inches simultaneously, useful when shopping across countries with different unit standards.
  • Removes the need to search separately for standard mattress dimension charts.

Common Mistakes

  • Assuming a US and UK mattress size with a similar name, like Queen and King, share identical dimensions, when they can differ in width, length, or both.
  • Buying bedding or a mattress protector based on the size name alone instead of checking the actual centimeter or inch dimensions.
  • Overlooking that Twin and Twin XL share the same width but differ in length by about 12.5 cm.

Edge Cases to Watch For

  • If no matching size is found in the lookup table, the calculator defaults to Queen dimensions (152 x 203 cm) rather than showing an error.
  • Real-world mattress dimensions can vary by a centimeter or two between manufacturers, so treat the output as a standard reference rather than an exact measurement of a specific product.
  • US and UK sizes sharing a similar name aren't identical: a US Queen and UK King are close in width but differ in length, so matching by name alone can be misleading.

Common Use Cases

  • Shoppers comparing mattress or bedding sizes between US and UK/European retailers.
  • People moving internationally who need to match existing bedding to a new mattress size.
  • Furniture buyers checking whether a bed frame's listed dimensions will fit a specific mattress size.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

How does a US Queen compare to a UK King?

A US Queen (152 x 203 cm) is close in width to a UK King (150 x 200 cm) but the UK King is slightly shorter - if you're buying bedding across countries, always check the exact centimeter dimensions rather than relying on the size name alone.

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Conclusion

Mattress size names don't translate directly between the US and UK/EU markets, so checking the actual centimeter and inch dimensions is the more reliable way to compare products. This calculator provides that reference instantly, while a manufacturer variance of a centimeter or two is still worth confirming against a specific listing.

References