Bed Size Calculator - Length, Width, and Standard Size

A bed size calculator turns a sleeper's height, region, and number of sleepers into a recommended mattress length, a per-sleeper width, and a matching standard size from the EU or US/AU chart. Use it when you are buying a new mattress for yourself, outfitting a guest room, sharing a bed with a partner, or checking whether a labeled size will actually fit the tallest person in the room.

• • Match a new mattress to your height: Enter the sleeper's height and region to get a minimum and recommended bed length, then read the matching size from the chart.
• • Plan a couple's or family bed: Set the sleeper count to 2 to see per-sleeper width, which tells you whether a Queen or King is wide enough for two adults.
• • Compare US and European sizes: Switch the region selector to see how the same person fits a 38 x 80 in Twin XL versus a 90 x 200 cm European single.
• • Check a guest room or short-stay setup: Use it before buying a guest bed to confirm a Full, a Queen, or a 140 x 200 cm will fit both an average adult and the room.

Bed labels can be misleading because the same word, such as Queen, can describe different lengths in different markets. Pairing a height-based recommendation with the standard chart removes the guesswork and avoids ordering a mattress that turns out to be too short for the sleeper.

The 20 cm buffer is the most widely cited comfort margin in mattress buying guides. It is the difference between a bed you can stretch out on and a bed that leaves your feet at the edge after a long night.

When you have the bed dimensions, the matching window treatments are easy to plan with a curtain size calculator once the headboard and frame widths are set.

The calculator combines a height-based length rule with a small standard-size chart for each region, then divides the recommended bed's width by the sleeper count.

• Region: Europe (cm standards) or North America / Australia (inch standards).
• Sleeper height: Height of the person who will use the bed, entered in centimeters or inches.
• Sleepers: One or two people sharing the bed. Drives the per-sleeper width output.
• Standard chart: Embedded list of standard mattress dimensions for the selected region. The calculator picks the smallest size that meets each length target.

The calculator rounds bed-length outputs to whole centimeters and whole inches because mattress labels are sold in those units. Per-sleeper width is also rounded because shoppers usually compare it to a labeled width.

If the comfortable length is longer than the longest bed in the chart, the calculator returns the longest size and notes that a custom extra-long mattress is the practical next step. This is common for adults over 200 cm (about 6 ft 7 in) shopping in the US chart.

According to the Sleep Foundation mattress size guide, adults over 6 feet tall (about 183 cm) should look for a bed with at least 80 inches of length, which is the same 20 cm (about 8 in) buffer this calculator adds to the sleeper's height.

After you have the right mattress size, the 90 minute sleep cycle calculator can help plan bedtime and wake time so the new bed is paired with a realistic sleep schedule.

Four ideas explain most bed-buying decisions: the length rule, region-specific sizes, per-sleeper width, and the room footprint.

If a sleeper is close to a chart boundary, both the minimum and comfortable results can land on different standard sizes. That is why the calculator reports two sizes: the smallest that meets the absolute minimum, and the smallest that meets the comfortable target.

Length is the most common reason to size up. Width is the most common reason to compare Queen and King when two adults share a bed.

Other rooms benefit from the same measurement-first approach, and a TV viewing distance calculator applies the same rule to the screen across from the bed.

Measure or look up the tallest person's height, then choose how many people will share the bed.

1. 1 Pick the right region: Choose Europe if you will buy a mattress in centimeters and North America / Australia if you will buy a mattress labeled in inches.
2. 2 Enter the tallest sleeper's height: Use centimeters or inches. The calculator accepts 80-220 cm or about 32-86 in.
3. 3 Set the sleeper count: Pick 1 sleeper for a single bed or 2 sleepers for a couple or shared guest setup.
4. 4 Read the recommended length: Compare the recommended length in cm and inches with the chart to find the smallest standard size that meets it.
5. 5 Check per-sleeper width: If two people share the bed, use the per-sleeper width to compare Queen, King, and California King.
6. 6 Measure the bedroom: Confirm the room has at least 60 cm (24 in) of clearance on the long sides and at the foot of the bed.

For a couple where the taller partner is 188 cm, this bed size calculator recommends a California King (72 x 84 in) for length. Per-sleeper width on a Queen (60 x 80 in) would be 76 cm, which is tight for restless adult sleepers, while a King (76 x 80 in) gives 96 cm per person.

Once you know the mattress footprint, a quilt calculator turns the same length and width into backing yardage, batting size, and binding requirements so the cover matches the bed without a custom order.

A short list of standard sizes is enough to pick a bed when length, width, and sleeper count are all checked.

• • Match the mattress to the sleeper: A height-based rule prevents buying a bed that is technically a standard size but still too short for the tallest person in the room.
• • Compare US and European markets: Region switching shows how the same adult fits a 90 x 200 cm single versus a 38 x 80 in Twin XL.
• • Plan a couple's bed with one number: Per-sleeper width turns the Queen vs King decision into a single comparison.
• • Quickly check guest and short-stay rooms: Use the same rule to decide whether a 140 x 200 cm double or a Full is enough for an occasional adult guest.
• • Spot room footprint early: Pairing length output with a quick room measurement avoids a too-large mattress in a small bedroom.

The calculator does not need a tape measure for length because the height input is personal. It still helps to measure the room before ordering, especially for King and California King frames.

If you are between two standard sizes, pick the one that meets the comfortable length first, then the wider one if both sleepers are restless.

Once the right size is in the room, a sleep debt calculator tracks whether the new mattress and schedule are reducing accumulated sleep loss.

Real bed choices are shaped by the sleeper, the room, and the brand. The factors below explain where the simple height rule can be tightened or loosened.

• • Standard sizes can vary by up to 2 cm or about 1 in between brands, so a labeled Queen from one maker can be slightly shorter than a labeled Queen from another.
• • The chart focuses on the most common EU and US/AU sizes. Specialty sizes such as Wyoming King, RV Short Queen, or UK Super King are not modeled, so check the manufacturer before buying.

For people over 200 cm (about 6 ft 7 in), a custom extra-long mattress is often the only comfortable option in the US chart, since the longest standard length is the California King at 84 in. The European chart usually has a 220 cm option that comes closer without a custom order.

A bed that meets both length and width goals but has a thin mattress for a heavier sleeper is still the wrong bed. Use this bed size calculator for the geometry of the mattress, then check the mattress thickness and support separately.

According to Wikipedia, Bed size, ISPA-standard US sizes and pan-European sizes differ in length and width even when the same name is used.

According to NIST SI Units, the international inch is exactly 2.54 centimeters, so all unit conversions in the calculator trace back to that definition.