Unit Converter
Direct answer. To convert square metres to square feet, multiply by 10.7639. To work out the square metres of a room, multiply length × width (both in metres) — a 4.2 m × 3.8 m living room is 15.96 m². To convert m³ to m² you need the depth as well — you can't convert directly between them.
What this unit converter does
This is a UK-friendly unit converter covering the seven categories everyday users actually need: length, mass/weight, temperature, area, volume, speed and digital storage. It handles the metric/imperial split that trips most British users up — square metres ↔ square feet, kilograms ↔ stones and pounds, metres ↔ feet and inches, °C ↔ °F, UK gallons ↔ litres ↔ US gallons. The conversion factor and formula are shown alongside every result.
Inputs explained
- Category: Length, Mass, Temperature, Area, Volume, Speed or Digital Storage.
- From Value: The numeric value you're converting. Decimals welcome.
- From Unit: The unit of your input (metres, kilograms, °C, etc.).
- To Unit: The target unit (feet, pounds, °F, etc.).
- Scientific Notation: Toggle for very small or very large numbers — useful for digital storage and scientific work.
How it works
For length, mass, area, volume, speed and digital storage, the converter uses a base-unit pivot — your input is first normalised to the SI base (metres, kilograms, m², m³, m/s, bytes), then converted from that base to your target unit. Temperature is the exception: because Celsius, Fahrenheit and Kelvin don't share a zero point, the conversion uses explicit affine formulas rather than a simple ratio. For area and volume, remember the conversion factor is the linear factor squared or cubed — that catches most people out.
Key formulas
Length / Mass / Volume: Result = Value × (From Factor ÷ To Factor)
Area: Linear factor SQUARED (m² → sq ft: ×10.7639, which is 3.2808²)
Volume: Linear factor CUBED (m³ → cubic ft: ×35.315, which is 3.2808³)
Temperature:
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
Area: Linear factor SQUARED (m² → sq ft: ×10.7639, which is 3.2808²)
Volume: Linear factor CUBED (m³ → cubic ft: ×35.315, which is 3.2808³)
Temperature:
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
K = °C + 273.15
Result
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Formula:
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Step-by-Step Example: Length Conversion
Input: 5 miles
Target Unit: kilometers
Step 1: 1 mile = 1609.344 meters (base unit).
Step 2: 5 miles = 5 × 1609.344 = 8046.72 meters.
Step 3: 1 kilometer = 1000 meters, so 8046.72 ÷ 1000 = 8.04672 km.
Result: 5 miles = 8.047 kilometers.
Step-by-Step Example: Temperature Conversion
Input: 98.6 °F
Target Unit: °C
Step 1: Apply formula: °C = (98.6 − 32) × 5/9
Step 2: °C = 66.6 × 5/9 = 37.0
Result: 98.6 °F = 37.0 °C (normal body temperature).
Use Cases
- Cooking: Convert recipe measurements between metric and imperial systems (grams to ounces, liters to cups).
- Travel: Convert miles to kilometers, Fahrenheit to Celsius, or gallons to liters when visiting countries using different systems.
- Science and engineering: Convert between SI and other unit systems for calculations, reports, or lab work.
- Computing: Convert between bytes, kilobytes, megabytes, gigabytes, and terabytes for storage planning.
- Fitness: Convert body weight between pounds and kilograms, or running distances between miles and kilometers.
Assumptions and Limitations
- Conversion factors are precise to at least 6 significant digits for physical units.
- Digital storage uses binary prefixes (1 KB = 1024 bytes), which is the convention used by operating systems and programming.
- Temperature conversion uses exact formulas, not approximations.
- The converter does not handle compound units (e.g., miles per gallon, kilowatt-hours) — only single units per category.
- Scientific notation can be toggled for results smaller than 0.001 or larger than 1,000,000.
UK imperial ↔ metric quick reference
Common conversions UK readers actually need — building, cooking, fitness, travel. Use the live converter above for the exact figure, or the tables below for fast reference.
| Quantity | Metric | Imperial / UK | Factor |
|---|---|---|---|
| Length | 1 metre | 3 ft 3 in (3.281 ft) | × 3.2808 |
| Length | 1 cm | 0.394 in | ÷ 2.54 |
| Area | 1 m² | 10.764 sq ft | × 10.7639 |
| Volume | 1 m³ | 1,000 litres / 220 UK gal | × 1,000 (L) |
| Volume | 1 litre | 1.76 UK pints / 0.22 UK gal | × 1.7598 |
| Mass | 1 kg | 2.205 lb (0.157 stone) | × 2.2046 |
| Mass | 10 kg | 1 st 8 lb | × 0.1574 |
| Speed | 100 km/h | 62.14 mph | ÷ 1.6093 |
| Temperature | 20 °C | 68 °F | × 9/5 + 32 |
Frequently Asked Questions
Multiply length by width, both in metres. So a UK living room of 4.2 m × 3.8 m gives you 15.96 m². For an L-shaped or odd-shaped room, split it into rectangles, calculate each separately, and add them up. If you only have measurements in feet, convert to metres first (1 ft = 0.3048 m) — or measure your tape in metres in the first place, which is what most modern UK retractable tapes show. Square metres are what you'll need for flooring, carpet, paint, tile and most UK building-related quotes.
Multiply square metres by 10.7639 to get square feet. So 50 m² is 538 sq ft, 100 m² is 1,076 sq ft, and a typical UK 2-bed flat at around 65 m² works out to roughly 700 sq ft. Going the other way, divide square feet by 10.7639 (or multiply by 0.092903). The factor is exactly the linear conversion squared — 3.28084² = 10.7639 — because you're converting a two-dimensional measure. UK property listings tend to give floor area in square metres now, but estate-agent particulars often still print square feet alongside.
Square metres (m²) measure area — a flat surface like a floor, wall or piece of land. Cubic metres (m³) measure volume — the space inside a three-dimensional object like a room, tank or shipping container. You can't convert one directly to the other because they measure different things, but if you know the depth or height, you can multiply: a 10 m² floor area at 2.4 m ceiling height gives a room volume of 24 m³. That's why builders need a third dimension (often slab depth) to turn an m² figure into an m³ concrete order, for example.
Multiply metres by 3.2808 to get feet. So 1.80 m is 5.91 ft — to get feet-and-inches, take the whole number of feet (5), then multiply the decimal portion (0.91) by 12 to get inches (about 11 in). So 1.80 m is 5 ft 11 in. Quick UK heights: 1.70 m = 5 ft 7 in, 1.75 m = 5 ft 9 in, 1.80 m = 5 ft 11 in, 1.85 m = 6 ft 1 in. Useful for translating between metric medical records and the feet-and-inches most adults still describe their own height in.
Multiply kilograms by 2.2046 to get pounds, then divide by 14 — the whole number is stones, the remainder is pounds. So 70 kg = 154.3 lb = 11 stone 0 lb. 80 kg = 12 st 8 lb. 100 kg = 15 st 10 lb. NHS settings use kg exclusively, but most UK adults still think about their weight in stones-and-pounds. Our dedicated stone/kg/pounds converter outputs in that composite format directly.
Multiply by 1,000 — 1 m³ = 1,000 litres exactly. So a 2 m³ water butt holds 2,000 litres, a typical 1,000-litre IBC is 1 m³, and a domestic heating oil tank of 2,500 litres works out at 2.5 m³. The factor is exact because the litre was originally defined as one cubic decimetre. For cubic feet, multiply m³ by 35.315 — useful for shipping volumes (CBM) and US-sourced specifications.
Multiply litres by 0.219969 for UK (imperial) gallons, or 0.264172 for US gallons. So 10 litres is 2.20 UK gallons or 2.64 US gallons — a 20% difference, which matters when comparing fuel economy: a UK car doing 50 mpg is the same as a US car doing 42 mpg, even though the litres-per-100km figure is identical. UK forecourts price fuel in pence per litre, but conversational MPG has stuck around since pre-decimalisation, so the gallon still gets quoted.
Multiply miles by 1.609344 — or 1.6 for a quick mental estimate. So 5 miles is 8.05 km, 10 miles is 16.09 km, 60 miles is 96.6 km. Going the other way, divide by 1.6093 (or multiply by 0.6214). A handy approximation for road signs abroad: a kilometre is roughly five-eighths of a mile, so a 50 km/h limit ≈ 31 mph, a 100 km/h motorway ≈ 62 mph. UK roads use miles and mph everywhere; almost all other European countries use km and km/h.
Use: °F = °C × 9/5 + 32. So 0°C is 32°F, 20°C is 68°F (room temperature), 30°C is 86°F (a heatwave in the UK), 100°C is 212°F (boiling). Quick mental shortcut: double the Celsius and add 30 — gets you within a degree or two for everyday weather temperatures. UK weather, oven recipes from UK or European sources, and most international scientific work use °C; older US recipes and weather forecasts use °F. Body temperature of 37°C ≈ 98.6°F.
Because area is two-dimensional — every dimension of length is doubled. If 1 m = 3.281 ft, then 1 m² = 3.281² = 10.764 ft², not just 3.281. Same logic for volume, where you cube the linear factor (1 m³ = 35.315 ft³ because 3.281³ = 35.315). Forgetting this is the single most common unit-conversion mistake — people try to convert hectares to acres or m² to sq ft using the linear factor and end up off by a factor of 3 to 30. A good converter handles it automatically; manual calculations need the right exponent.
Sources and References
- NIST Special Publication 811 – Guide for the Use of the International System of Units — Official U.S. reference for SI unit definitions and conversion factors.
- Bureau International des Poids et Mesures (BIPM) – The SI — International authority defining the metric system and SI base units.
- NIST Handbook 44 – Specifications for Weighing and Measuring Devices — U.S. standards for measurement conversions used in commerce.
- IEC 80000-13 – Quantities and Units for Information Technology — International standard defining binary prefixes for digital storage units.
- Schema.org FAQPage Specification — Structured data standard for the FAQ section markup.