Inches to Feet Calculator
Convert between inches, feet, centimetres, and metres instantly. Perfect for height conversion, TV screen sizes, and construction measurements. 1 inch = 2.54 cm exactly — 1 foot = 12 inches = 30.48 cm.
Common Heights in Feet, Inches, and Centimetres
| Height (ft & in) | Total Inches | Centimetres | Metres |
|---|---|---|---|
| 4' 0" | 48" | 121.9 cm | 1.219 m |
| 4' 6" | 54" | 137.2 cm | 1.372 m |
| 5' 0" | 60" | 152.4 cm | 1.524 m |
| 5' 2" | 62" | 157.5 cm | 1.575 m |
| 5' 4" | 64" | 162.6 cm | 1.626 m |
| 5' 6" | 66" | 167.6 cm | 1.676 m |
| 5' 8" | 68" | 172.7 cm | 1.727 m |
| 5' 9" | 69" | 175.3 cm | 1.753 m |
| 5' 10" | 70" | 177.8 cm | 1.778 m |
| 5' 11" | 71" | 180.3 cm | 1.803 m |
| 6' 0" | 72" | 182.9 cm | 1.829 m |
| 6' 2" | 74" | 187.9 cm | 1.879 m |
| 6' 4" | 76" | 193.0 cm | 1.930 m |
| 6' 6" | 78" | 198.1 cm | 1.981 m |
| 7' 0" | 84" | 213.4 cm | 2.134 m |
Inch and Foot: History and Definition
The inch and foot are among the oldest units of length used in Britain, with histories stretching back thousands of years. The foot was originally based on the human foot, while the inch was defined as the width of a man's thumb at the base. Historical definitions varied significantly by region and era.
The modern definition was fixed by the International Yard and Pound Agreement of 1959, signed by the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa. It defined:
- 1 inch = 2.54 centimetres exactly
- 1 foot = 12 inches = 30.48 cm exactly
- 1 yard = 3 feet = 0.9144 metres exactly
UK Height Measurement: Feet or Centimetres?
The UK officially uses metric measurements for length under the Weights and Measures Act 1985, and the NHS records patient height in centimetres and metres. Yet the vast majority of British adults know and state their height in feet and inches rather than centimetres.
Surveys consistently show that over 70% of UK adults know their height in feet and inches, compared to under 30% who know it in cm. This is unique to Britain — continental Europeans typically use only cm, while Americans use only feet and inches. Britain occupies a curious middle position, officially metric but culturally imperial for height and body measurements.
The NHS has adapted to this reality. Many NHS height and weight charts display both metric and imperial. GP practice nurses routinely have patients who say "I'm 5 foot 8" and then convert this to 172.7 cm for the clinical record. The NHS's own BMI calculator accepts height in either feet/inches or centimetres.
Fraction Inches to Millimetres Reference Table
For woodworking, plumbing, engineering, and general DIY, fractions of an inch are commonly used in imperial measurement. Here is the complete reference table:
| Fraction | Decimal Inches | Millimetres | Common Use |
|---|---|---|---|
| 1/16" | 0.0625" | 1.588 mm | Fine tolerances, shims |
| 1/8" | 0.125" | 3.175 mm | Tile grout width, small drill bits |
| 3/16" | 0.1875" | 4.763 mm | Woodworking grooves |
| 1/4" | 0.25" | 6.350 mm | Common bolt size, BSP fittings |
| 3/8" | 0.375" | 9.525 mm | Common pipe thread (UK plumbing) |
| 1/2" | 0.5" | 12.700 mm | Standard garden hose, copper pipe |
| 5/8" | 0.625" | 15.875 mm | Timber batten thickness |
| 3/4" | 0.75" | 19.050 mm | Plywood thickness, door handle height reference |
| 7/8" | 0.875" | 22.225 mm | Structural engineering tolerances |
| 1" | 1.000" | 25.400 mm | Reference unit |
TV and Screen Sizes: Inches to cm
Television screen sizes are measured diagonally in inches worldwide, including in the UK. This is one area where imperial measurement remains genuinely universal — even in fully metric countries, TVs are sold with inch diagonal measurements. Here are the most common UK TV sizes with their metric equivalents:
| Diagonal (inches) | Diagonal (cm) | Width (cm) 16:9 | Height (cm) 16:9 |
|---|---|---|---|
| 24" | 61.0 cm | 53.1 cm | 29.9 cm |
| 32" | 81.3 cm | 70.8 cm | 39.8 cm |
| 40" | 101.6 cm | 88.5 cm | 49.8 cm |
| 43" | 109.2 cm | 95.1 cm | 53.5 cm |
| 50" | 127.0 cm | 110.6 cm | 62.2 cm |
| 55" | 139.7 cm | 121.6 cm | 68.4 cm |
| 65" | 165.1 cm | 143.8 cm | 80.9 cm |
| 75" | 190.5 cm | 165.9 cm | 93.3 cm |
| 85" | 215.9 cm | 188.0 cm | 105.7 cm |
The viewing distance recommendation is approximately 1.5 to 2.5 times the screen diagonal. For a 55" (139.7 cm) TV, ideal viewing distance is roughly 210 cm to 350 cm (7 to 11.5 feet).
Construction and Building: Decimal Feet vs Feet and Inches
UK building regulations and planning permissions officially require metric measurements in millimetres and metres. A standard UK internal door height is 1981 mm (6'6") and width is 762 mm (2'6") or 838 mm (2'9"). However, many builders, joiners, and DIY enthusiasts continue to work in imperial, particularly for timber, where traditional UK sizes (2 × 4, 3 × 2) remain in common use even though the actual timber is now sold in metric dimensions.
In US construction, dimensions are typically stated as feet and inches with a hyphen — for example, 8'-6" (8 feet 6 inches). In UK drawings, the same dimension would appear as 2591 mm. The decimal feet system (8.5 feet) is used in surveying and some engineering contexts but is uncommon in UK construction.
Common construction reference points:
- Standard ceiling height UK: 2400 mm = 7'10.6"
- Older UK property ceiling height: 2700-3000 mm = 8'10" to 9'10"
- Standard UK door width: 762 mm = 2'6" (762) or 838 mm = 2'9"
- Standard UK door height: 1981 mm = 6'6"
- Standard UK brick: 215 mm × 102.5 mm × 65 mm = approx. 8.5" × 4" × 2.5"
UK vs Metric: The Weights and Measures Act 1985
The Weights and Measures Act 1985 required the UK to use metric measurements for most commercial purposes. For length, this meant that road signage retained miles (specifically exempted), but most other length measurements in commerce had to transition to metric. Fabric sold by the metre replaced fabric sold by the yard. Timber sold in millimetres replaced timber sold in feet and inches — at least officially.
The practical reality is more complex. Tiles are often described in centimetres or metric (600mm × 300mm), plumbing is largely described in metric (22mm copper pipe), yet many everyday conversations still happen in inches. Screen sizes in inches, tyre widths in mm with aspect ratio and rim size in inches (e.g., 205/55 R16), road widths in feet, and human height in feet and inches all persist in everyday British usage.
Post-Brexit, the UK has relaxed some metrication requirements, allowing imperial units to be displayed more prominently on goods again. Miles will remain on road signs indefinitely.
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Frequently Asked Questions
There are exactly 12 inches in one foot. Since 1959, the inch has been defined as 2.54 cm exactly, making 1 foot = 12 × 2.54 = 30.48 cm exactly. There are 3 feet in a yard (91.44 cm) and 5280 feet in a mile (1.60934 km). To convert feet to inches, multiply by 12. To convert inches to feet, divide by 12 (and the remainder is inches).
5 feet 9 inches = 175.26 cm. The calculation: (5 × 30.48) + (9 × 2.54) = 152.4 + 22.86 = 175.26 cm. This is approximately the average UK male height (175.3 cm according to NHS data). In total inches, 5'9" = (5 × 12) + 9 = 69 inches. In metres: 175.26 ÷ 100 = 1.7526 m.
The UK officially uses centimetres and metres (the NHS records height in cm), but most British people describe their height informally in feet and inches. This is culturally embedded despite metrication — over 70% of UK adults know their height in feet and inches, compared to fewer knowing it in cm. The UK is unusual in having both: official metric records but widespread informal imperial use. Americans use only feet and inches; most of Europe uses only cm.
One quarter inch (1/4") equals exactly 6.35 mm. Since 1 inch = 25.4 mm exactly: 1/4 × 25.4 = 6.35 mm. Key fractions: 1/8" = 3.175 mm; 1/4" = 6.35 mm; 3/8" = 9.525 mm; 1/2" = 12.7 mm; 3/4" = 19.05 mm; 1" = 25.4 mm. These are essential for imperial plumbing (BSP threads), woodworking, and DIY in the UK where many older fittings and tools use imperial measurements.
A 55-inch TV has a diagonal screen measurement of 139.7 cm (55 × 2.54 = 139.7 cm). At the standard 16:9 aspect ratio, the screen is approximately 121.6 cm wide and 68.4 cm tall. TV screens are measured diagonally in inches worldwide, including in metric countries — this is one area where imperial measurement is genuinely universal. The recommended viewing distance for a 55-inch TV is approximately 2.1 to 3.5 metres.
UK construction drawings officially use millimetres and metres (e.g., a room shown as 4200 mm × 3600 mm). US construction drawings use feet and inches, often written with a hyphen (e.g., 13'-9" × 11'-9.7"). Many UK builders still use imperial informally, particularly for timber sizes (referring to 4 × 2 timber instead of 100 × 50 mm), and plasterboard sheets are still commonly described as "8 × 4" (2400 × 1200 mm). Planning applications in the UK must use metric by law.
6 feet equals exactly 182.88 cm (6 × 30.48 = 182.88 cm). In total inches, 6 feet = 72 inches. In metres, 6 feet = 1.8288 m. Being "6 feet tall" is often seen as a significant height milestone in UK culture — a height that many men aspire to. In the UK male population, approximately 14% of men are 6 feet or taller, according to NHS Health Survey data.