Bed Size Calculator for Odd Shaped Bedrooms
If your bedroom has an irregular shape caused by a chimney breast, alcoves or sloping ceilings, choosing the right bed size is essential to maintain at least 70cm of clear circulation space on the main access sides. This guide gives you a straightforward calculator method using exact UK mattress dimensions so you can measure once, calculate circulation gaps and select a bed that fits without blocking movement or doors.
Why Odd Shaped Bedrooms Need Specific Calculations
Standard rectangular rooms allow easy placement of a double bed, but chimney breasts can reduce usable width while alcoves often limit length. Sloping ceilings may restrict headroom above the bed headboard. Without measuring and subtracting these intrusions you risk buying a bed that leaves less than 60cm clearance, making it difficult to change bedding or walk around safely.
Standard UK Bed Sizes and Circulation Rules
Use these exact UK sizes when calculating:
- Small single: 75x190cm (2ft6)
- Single: 90x190cm (3ft)
- Small double: 120x190cm (4ft)
- Double: 135x190cm (4ft6)
- King: 150x200cm (5ft)
- Super king: 180x200cm (6ft)
Rule of thumb: allow minimum 70cm on at least two sides for circulation, 90cm on the door side if the bed blocks the entrance swing. For sloping ceilings ensure the chosen position gives 120cm vertical clearance above the mattress surface where you sit up.
Simple Bed Size Calculator Method
Step-by-step process:
- Measure the clearest rectangular area in your room, noting exact positions of chimney, alcoves and lowest ceiling point in centimetres.
- Decide primary access sides (usually both long sides or one long and the foot).
- Add bed width plus 2 × 70cm clearance; this must be less than or equal to your measured room width at that point.
- Repeat for length: bed length plus 70cm at foot (or 90cm if against a door) must fit the available length.
- If sloping ceiling is involved, measure height 100cm in from walls and reject any bed position where clearance is under 120cm when sitting.
Example: room width 280cm with 40cm chimney protrusion on one side leaves 240cm usable. A 150cm king bed plus 140cm clearance (70cm each side) totals 290cm – too big. Switch to 135cm double bed which totals 275cm and still fails, so a 120cm small double (total 260cm) works with 20cm spare.
Bed Size Comparison Table for Odd Rooms
| Bed Size | Width cm | Length cm | Minimum Room Width Needed (70cm both sides) | Best For |
|---|---|---|---|---|
| Single | 90 | 190 | 230 | Narrow alcove rooms |
| Small Double | 120 | 190 | 260 | Chimney breast rooms |
| Double | 135 | 190 | 275 | Standard odd layouts |
| King | 150 | 200 | 290 | Larger rooms with shallow alcoves |
Space-Saving Solutions for Tight or Sloping Rooms
In rooms with severe restrictions consider beds that maximise floor space. L-shaped bunk beds tuck one sleeper into an alcove while the other uses the open area. For adults, storage beds reduce the need for extra bedroom furniture that would further crowd an irregular layout. Check the maximum mattress depth allowed by the bed maker to comply with BS EN 747 guard-rail rules on any bunk.
Recommended Beds for Irregular Bedrooms
These models suit odd-shaped rooms because their compact footprints or clever configurations work around chimneys and alcoves.
The Noomi Tera Single/Double L Shaped Bunk Bed (FSC-Certified) places one bed in a corner or alcove, freeing the centre of small or sloping rooms.
The Flair Hampton L-Shaped Bunk Bed with Storage & Wardrobe combines storage and sleeping in one L-shaped unit, ideal when a chimney breast has already reduced usable wall space.
For grown-up rooms that still feel tight, a king size ottoman bed offers hidden storage so you can remove chests of drawers that would otherwise obstruct circulation paths.
If the odd shape is caused by a chimney in a child’s room, the Flair Wizard Junior L Shaped Bunk Bed keeps the footprint small while meeting the 16cm guard-rail requirement when used with appropriate mattress depths.
Practical Checklist Before You Buy
- Measure twice at floor level and again at mattress height to catch sloping walls.
- Mark the proposed bed outline on the floor with masking tape and walk around it.
- Check door swing clearance remains at least 60cm when the bed is in position.
- Confirm the bed meets UK fire safety regulations (BS 7177 for mattresses).
- For bunk beds, verify the stated maximum mattress depth keeps the top-bunk guard rail at least 16cm above the mattress.
- Leave extra space if the room will also hold bedroom furniture such as a wardrobe or chest.
Following these steps prevents the common mistake of ordering a king size bed only to discover it leaves just 40cm on one side of a chimney breast.
Our picks for this guide
- Noomi Tera Single/Double L Shaped Bunk Bed (FSC-Certified) – Its L-shaped design fits neatly into alcoves or around chimney breasts while preserving essential circulation space in odd-shaped children's bedrooms.
- Flair Hampton L-Shaped Bunk Bed with Storage & Wardrobe – Built-in storage and wardrobe reduce the need for extra furniture, maximising movement space in rooms narrowed by sloping ceilings or chimneys.
- Flair Wizard Junior L Shaped Bunk Bed – Compact junior L-shape is ideal for smaller odd-shaped rooms, meeting the 16cm guard-rail rule when paired with suitable mattress depth.
- King Size Ottoman Beds – Hidden storage eliminates extra bedroom furniture that would crowd circulation paths around chimney breasts or alcoves.
Frequently asked questions
What is the minimum circulation space needed around a bed in an odd-shaped UK bedroom?
Aim for at least 70cm on the two main access sides. Where a door opens against the bed, increase that side to 90cm so the door can open fully. In rooms with sloping ceilings add a vertical clearance check of 120cm above the mattress where you will sit.
Can I fit a super king bed in a room with a chimney breast?
Only if the clear width after subtracting the chimney depth is at least 320cm (180cm bed + 140cm circulation). Most chimney breasts make this impossible; a king or smaller size is usually the realistic maximum.
Are L-shaped bunk beds a good choice for alcove bedrooms?
Yes. The L shape lets one sleeper occupy the alcove while the other uses the open floor area. Models such as the Flair and Noomi ranges are designed for exactly this type of irregular layout and meet BS EN 747 safety standards.
How do I calculate space when the ceiling slopes over the bed?
Measure the height 100cm in from each wall. Any point where the ceiling is lower than 120cm above the mattress surface when sitting up is unsuitable for the head of the bed. Adjust position or choose a smaller size.
Should I buy a storage bed for an irregularly shaped room?
Storage beds are useful because they remove the need for additional chests or drawers that would further reduce circulation space around chimneys or in alcoves. Ottoman styles are particularly effective in tight layouts.
Related guides
- Small Double Bed Room Size Requirements UK
- How to Fit a King Size Bed in a Small Room: Realistic UK Advice
- Guest Room Bed Size Guide: Choosing the Right Bed for Visitors
- Choosing Beds for Sloped Ceiling Bedrooms: Layout Tips and Bed Ideas
- Bed Measurement Guide for Small Bedrooms: How Much Space Do You Really Need
- Bed Layout Solutions for Narrow Long Bedrooms