Free Bed Size Calculator

Determining the Right Bed Size Based on Your Height

When shopping for a new mattress, one of the most common questions is “What size bed do I need?” A bed size calculator — also referred to as a mattress size calculator or bed size guide — provides a straightforward answer by factoring in your height and your region’s standard dimensions. This tool helps you find the bed dimensions that will offer you the most comfortable sleep, ensuring you have enough room to stretch without your feet hanging off the edge.

The Rule for Ideal Mattress Length

The core principle behind selecting the correct mattress length is simple: your bed should be long enough to accommodate your entire body plus some extra space for flexibility. The general guideline is to add at least 20 cm (roughly 8 inches) to your height. This extra length allows you to lie flat and move comfortably, preventing the sensation of being cramped.

Expressed as a formula:

$$\text{Comfortable Bed Length} = \text{Height} + 20\ \text{cm}$$

For example, if you are 180 cm tall, you would aim for a mattress length of 200 cm or more. The calculator uses this rule to suggest both a minimum and a comfortable length based on your input.

Width: A Personal Choice

While the length can be determined quite objectively using the height rule, width is much more subjective. The ideal bed width depends on several factors:

• Your sleeping style and how much you move during the night.
• Your body size and whether you share the bed with a partner or pets.
• The available floor space in your bedroom.

A narrower bed (e.g., 90–120 cm) may be sufficient for a single sleeper who doesn’t move much, while a wider bed (150 cm or more) offers more freedom and is better for couples.

Standard Mattress Sizes Across Markets

Mattress sizes vary by region. The following table compares the most common mattress sizes available in Europe and North America/Australia. Use this bed dimensions reference to match the length suggested by the calculator with a standard size, and then decide on the width that fits your needs.

Geographic Market	Dimensions (cm)	Dimensions (in)	US Standard Name
Europe	80 × 120	31.5″ × 47.2″
Europe	90 × 120	35.4″ × 47.2″
Europe	100 × 120	39.4″ × 47.2″
Europe	120 × 120	47.2″ × 47.2″
Europe	140 × 120	55.1″ × 47.2″
Europe	160 × 120	63.0″ × 47.2″
Europe	180 × 120	70.9″ × 47.2″
Europe	200 × 120	78.7″ × 47.2″
Europe	80 × 140	31.5″ × 55.1″
Europe	90 × 140	35.4″ × 55.1″
Europe	100 × 140	39.4″ × 55.1″
Europe	120 × 140	47.2″ × 55.1″
Europe	140 × 140	55.1″ × 55.1″
Europe	160 × 140	63.0″ × 55.1″
Europe	180 × 140	70.9″ × 55.1″
Europe	200 × 140	78.7″ × 55.1″
Europe	80 × 160	31.5″ × 63.0″
Europe	90 × 160	35.4″ × 63.0″
Europe	100 × 160	39.4″ × 63.0″
Europe	120 × 160	47.2″ × 63.0″
Europe	140 × 160	55.1″ × 63.0″
Europe	160 × 160	63.0″ × 63.0″
Europe	180 × 160	70.9″ × 63.0″
Europe	200 × 160	78.7″ × 63.0″
Europe	80 × 180	31.5″ × 70.9″
Europe	90 × 180	35.4″ × 70.9″
Europe	100 × 180	39.4″ × 70.9″
Europe	120 × 180	47.2″ × 70.9″
Europe	140 × 180	55.1″ × 70.9″
Europe	160 × 180	63.0″ × 70.9″
Europe	180 × 180	70.9″ × 70.9″
Europe	200 × 180	78.7″ × 70.9″
Europe	80 × 190	31.5″ × 74.8″
Europe	90 × 190	35.4″ × 74.8″
Europe	100 × 190	39.4″ × 74.8″
Europe	120 × 190	47.2″ × 74.8″
Europe	140 × 190	55.1″ × 74.8″
Europe	160 × 190	63.0″ × 74.8″
Europe	180 × 190	70.9″ × 74.8″
Europe	200 × 190	78.7″ × 74.8″
Europe	80 × 200	31.5″ × 78.7″
Europe	90 × 200	35.4″ × 78.7″
Europe	100 × 200	39.4″ × 78.7″
Europe	120 × 200	47.2″ × 78.7″
Europe	140 × 200	55.1″ × 78.7″
Europe	160 × 200	63.0″ × 78.7″
Europe	180 × 200	70.9″ × 78.7″
Europe	200 × 200	78.7″ × 78.7″
Europe	80 × 220	31.5″ × 86.6″
Europe	90 × 220	35.4″ × 86.6″
Europe	100 × 220	39.4″ × 86.6″
Europe	120 × 220	47.2″ × 86.6″
Europe	140 × 220	55.1″ × 86.6″
Europe	160 × 220	63.0″ × 86.6″
Europe	180 × 220	70.9″ × 86.6″
Europe	200 × 220	78.7″ × 86.6″
Europe	80 × 240	31.5″ × 94.5″
Europe	90 × 240	35.4″ × 94.5″
Europe	100 × 240	39.4″ × 94.5″
Europe	120 × 240	47.2″ × 94.5″
Europe	140 × 240	55.1″ × 94.5″
Europe	160 × 240	63.0″ × 94.5″
Europe	180 × 240	70.9″ × 94.5″
Europe	200 × 240	78.7″ × 94.5″
North America / Australia	71 × 132	28″ × 52″	Crib
North America / Australia	97 × 190	38″ × 75″	Twin
North America / Australia	97 × 203	38″ × 80″	Twin XL
North America / Australia	135 × 190	53″ × 75″	Full
North America / Australia	135 × 203	53″ × 80″	Full XL
North America / Australia	152 × 203	60″ × 80″	Queen
North America / Australia	168 × 203	66″ × 80″	Olympic Queen
North America / Australia	193 × 203	76″ × 80″	King
North America / Australia	183 × 213	72″ × 84″	California King
North America / Australia	203 × 249	80″ × 98″	Texas King

Note: In Europe, mattress sizes do not have standardized names like in the US; they are typically referred to by their dimensions. The “US Standard Name” column applies only to the North American / Australian rows.

How to Use the Bed Size Calculator

Using the tool is straightforward:

1. Select your region: Choose between Europe or North America / Australia. This ensures the results are matched to the standard sizes available in your market.
2. Enter your height: Input your height in the preferred unit (centimeters or inches). The calculator accepts heights ranging from 80 cm to 220 cm.
3. Review the suggestions: The calculator displays both a minimum recommended length (your height plus about 10–15 cm of extra space) and a comfortable length (your height + 20 cm). For example, if you are 180 cm tall, the comfortable length would be 200 cm.
4. Match to a standard size: Compare the suggested length with the bed dimensions in the table above. Identify which standard mattress length (e.g., 190 cm, 200 cm, 220 cm) is closest to your comfortable length.
5. Choose your width: Once you have the length, decide on the width based on your sleeping habits and room space. The calculator does not prescribe a width, but the table can help you see available widths for your chosen length.

Final Considerations

Finding the right mattress size is essential for sleep quality. This free online mattress size guide ensures that your new bed provides adequate length for your height, while giving you the flexibility to select a width that suits your personal comfort needs. Whether you are looking for a what size bed do I need answer for yourself, a partner, or a child, this bed size guide simplifies the decision process.