Bed Size Calculator

Find the minimum and ideal mattress length from your height, then compare the result against common bed sizes used in your region.

Omni's guidance is simple: your mattress should be at least your height, and ideally about 20 cm longer.

Recommended Mattress Length

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Run the calculation to see the recommended length and a matching bed size.

Quick Answer

A comfortable mattress should be at least as long as you are, and ideally 20 cm or about 8 inches longer for easy sleeping posture and pillow space.

How to Calculate Bed Size

  1. Measure your height.
  2. Choose centimeters or inches.
  3. Pick your region.
  4. Click Calculate to get the ideal mattress length and a standard size suggestion.

Formula

Minimum length = your height

Ideal length = your height + 20 cm, or height + 8 inches

Worked Examples

Example 1: A 183 cm tall sleeper should look for at least a 183 cm bed and ideally a 203 cm bed.

Example 2: A 72 inch sleeper should look for at least a 72 inch bed and ideally an 80 inch bed.

Example 3: A taller sleeper may need a 220 cm or 84 inch long mattress for maximum comfort.

How to Interpret the Result

Output Meaning
Minimum lengthThe shortest mattress length you should consider.
Ideal lengthA more comfortable mattress length for everyday use.
Standard sizeA common commercial size that is close to the ideal length.

Frequently Asked Questions

That is the comfort margin Omni recommends so your feet and pillow have enough room.

Yes. North American beds, European beds, and UK beds often use different standard lengths.

Not always, but a longer mattress is usually more comfortable if you have the room and budget for it.

Related Calculators

References

  • OmniCalculator reference page
  • The reference page recommends adding 20 cm or about 8 inches to your height for comfort.
  • Last reviewed: March 2026.