Last updated: February 2026

Square Metre Calculator

Calculate area in m² for UK property, flooring, painting, and gardening projects

Rectangle or Square Area

Quick Flooring Tip

When ordering flooring, always add 10% extra for wastage on straight laying, or 15% extra for diagonal patterns. For carpet, add at least 5% for seaming and fitting.

UK Average Room Sizes 2025

Understanding typical UK room dimensions helps you plan renovations, compare properties, and estimate material requirements. These figures are based on RIBA research and property market data.

Room Type UK Average (m²) In Square Feet Minimum (Building Regs)
Single Bedroom 8-10 m² 86-108 ft² 6.5 m² (70 ft²)
Double Bedroom 12-15 m² 129-161 ft² 10.2 m² (110 ft²)
Master Bedroom 15-20 m² 161-215 ft² 11.5 m² (124 ft²)
Living Room 17-25 m² 183-269 ft² 12 m² (129 ft²)
Kitchen 10-15 m² 108-161 ft² 5.5 m² (59 ft²)
Bathroom 4-6 m² 43-65 ft² 2.5 m² (27 ft²)
En-suite 3-4 m² 32-43 ft² 1.5 m² (16 ft²)
Home Office 6-9 m² 65-97 ft² 5 m² (54 ft²)
Garage (Single) 15-18 m² 161-194 ft² 15 m² (161 ft²)

New-Build vs Period Properties

UK new-build homes have shrunk significantly. The average new-build living room is now just 15.8 m², compared to 24 m² in Victorian homes. When house hunting, always check actual room dimensions rather than relying on marketing descriptions.

Area Calculation Formulas

Different shapes require different formulas. Here's how to calculate area for common shapes you'll encounter in property and DIY projects:

Rectangle / Square

Area = Length × Width

Example: Room 5m × 4m = 20 m²

Circle

Area = π × r²

Example: Radius 3m → 3.14159 × 9 = 28.27 m²

Triangle

Area = ½ × Base × Height

Example: Base 6m, Height 4m → 0.5 × 6 × 4 = 12 m²

Trapezoid

Area = ½ × (a + b) × h

Example: Parallel sides 3m & 5m, Height 4m → 0.5 × 8 × 4 = 16 m²

Measuring L-Shaped Rooms

For L-shaped, T-shaped, or irregular rooms, divide the space into simple rectangles. Calculate each rectangle's area separately, then add them together for the total. Always measure at floor level, not at skirting board height.

Area Unit Conversion Reference

UK property agents often mix metric and imperial measurements. Use this table to convert between common area units:

Unit = Square Metres (m²) = Square Feet (ft²)
1 Square Metre (m²) 1 10.764
1 Square Foot (ft²) 0.0929 1
1 Square Yard (yd²) 0.8361 9
1 Square Inch (in²) 0.000645 0.00694
1 Acre 4,046.86 43,560
1 Hectare 10,000 107,639

Quick Mental Conversions

  • m² to ft²: Multiply by 10.8 (or roughly ×11 for quick estimate)
  • ft² to m²: Divide by 10.8 (or roughly ÷11)
  • Acres to m²: Multiply by 4,047
  • Hectares to acres: Multiply by 2.47

UK Material Coverage Guide

Knowing how much material you need prevents costly over-ordering or frustrating project delays. Here's typical coverage for common home improvement materials:

Emulsion Paint

10-12 m² per litre
2.5L covers ~25 m² (one coat)

Wood Stain/Varnish

12-15 m² per litre
Varies by wood porosity

Wall Tiles

Add 10-15% extra
For cuts and breakages

Laminate Flooring

Add 10% extra
15% for diagonal laying

Carpet

Add 5-10% extra
Check roll width (4m/5m)

Plasterboard

2.88 m² per sheet
Standard 1.2m × 2.4m

Grass Seed

20-35g per m²
1kg covers ~30-50 m²

Paving Slabs (600×600mm)

2.78 slabs per m²
Add 5% for cuts

Paint Coverage Calculator

To calculate paint needed for a room:

  1. Measure wall height × room perimeter (all four walls)
  2. Subtract window and door areas
  3. Multiply by number of coats (usually 2)
  4. Divide by paint coverage rate (10-12 m²/litre)

Example: Typical UK Bedroom

Room: 4m × 3m, ceiling height 2.4m
Wall area: (4+3+4+3) × 2.4 = 33.6 m²
Minus door & window: ~4 m²
Paintable area: 29.6 m²
For 2 coats: 59.2 m² coverage needed
Paint required: 59.2 ÷ 11 = 5.4 litres (buy 5L + 1L)

UK Garden Size Guide

Garden size varies hugely across the UK by region and property type. Here's what to expect:

Property Type Average Garden (m²) In Square Feet
Terraced House 90 m² 969 ft²
Semi-Detached 160 m² 1,722 ft²
Detached House 290 m² 3,122 ft²
Flat (with garden) 40 m² 431 ft²
UK Average (all types) 188 m² 2,024 ft²

Regional Variations

Region Average Garden Size Compared to UK Average
London 140 m² -26%
South East 175 m² -7%
Midlands 195 m² +4%
North of England 210 m² +12%
Wales 230 m² +22%
Scotland 250 m² +33%

Frequently Asked Questions

How do I calculate square metres?

To calculate square metres, multiply the length by the width in metres. For example, a room 5m long and 4m wide = 5 × 4 = 20 m². For irregular shapes, divide into rectangles, calculate each separately, and add together. If measuring in feet, calculate in feet first then divide by 10.764 to convert to m².

How many square feet are in a square metre?

One square metre equals 10.764 square feet. To convert sq ft to sq m, divide by 10.764. To convert sq m to sq ft, multiply by 10.764. For quick mental maths, you can roughly multiply m² by 11 to get ft², or divide ft² by 11 to get m².

What is the average UK living room size?

The average UK living room is 17 m² (183 ft²). New-build homes average 15.8 m², while Victorian and Edwardian period homes typically have living rooms of 20-30 m². The minimum recommended living room size according to RIBA (Royal Institute of British Architects) is 12 m² for a 1-bed flat.

How much flooring do I need for my room?

Calculate your floor area in m², then add extra for wastage. Add 10% for straight laying with simple room shapes, or 15% for diagonal/herringbone patterns or rooms with many alcoves. For example, a 20 m² room with straight laying needs 20 × 1.10 = 22 m² of flooring. Always round up to the nearest pack size.

How many litres of paint per square metre?

Most emulsion paints cover 10-12 m² per litre on smooth surfaces. Textured surfaces or first coats on bare plaster may only cover 6-8 m² per litre. For a typical UK bedroom (12 m² floor area with 2.4m ceiling height), you'd need about 5 litres for two coats on the walls, plus 2 litres for the ceiling.

What's the minimum bedroom size in UK regulations?

UK building regulations require a minimum 6.5 m² (70 ft²) for a single bedroom and 10.2 m² (110 ft²) for a double bedroom. For HMO (Houses in Multiple Occupation) licensing, rooms must be at least 6.51 m² for one person and 10.22 m² for two people. The ceiling height must be at least 2.1m for at least half the floor area.

How do I measure an L-shaped room?

Divide the L-shape into two rectangles. Measure length × width for each rectangle separately, then add them together. For example: Rectangle 1 (5m × 3m = 15 m²) + Rectangle 2 (4m × 2m = 8 m²) = 23 m² total. Draw a sketch first to avoid measuring errors, and always measure at floor level.

How many square metres is a standard UK garden?

The average UK garden is approximately 188 m² (2,024 ft²), though this varies enormously. London averages just 140 m², while Scotland averages 250 m². Terraced houses typically have 90 m² gardens, while detached homes average 290 m². New-build gardens are often smaller at around 100-150 m².

UC

Reviewed by: UK Calculator, Founder & Developer

Founder & Developer - UKCalculator.com

The UK Calculator team is the founder and developer of UKCalculator.com, providing free, accurate calculators for UK residents.

Last Updated: January 2025 | Next Review: July 2025

This calculator provides estimates for planning purposes. For legal property measurements, always consult a qualified surveyor.

Expert Reviewed — This calculator is reviewed by our team of financial experts and updated regularly with the latest UK tax rates and regulations. Last verified: February 2026.

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