A foot is an imperial and US customary unit of length equal to 12 inches. It is widely used for human height, room dimensions, construction, real estate, aviation altitude, sports fields, and everyday measurements in the United States.
Quick facts
- Unit name
- foot
- Plural
- feet
- Symbol
- ft
- Quantity
- length
- System
- imperial and US customary
- Exact inch relation
- 1 ft = 12 in
- Exact metric relation
- 1 ft = 0.3048 m
- Yard relation
- 3 ft = 1 yd
Visual scale
One foot is about the scale of a large step or a short ruler. It is larger than an inch but smaller than a yard or meter.
Definition and exact value
The modern foot is exactly 12 inches. Because one inch equals exactly 2.54 centimeters, one foot equals exactly 30.48 centimeters or 0.3048 meters.
Symbol and writing rules
The standard symbol is ft. A prime mark can appear in dimensions, as in 6', but ft is clearer in technical text and conversion tables. Do not pluralize the symbol: write 6 ft, not 6 fts.
Feet and inches notation
Feet are often written together with inches for human height and construction dimensions. For example, 5 ft 10 in means 5 feet plus 10 inches, or 70 inches total.
| Notation | Total inches | Meters | Typical context |
|---|---|---|---|
| 1 ft | 12 in | 0.3048 m | small dimensions |
| 5 ft 10 in | 70 in | 1.778 m | human height |
| 8 ft | 96 in | 2.4384 m | room height, lumber |
How big is one foot?
A foot is convenient for human-scale measurements. It is smaller than a meter but large enough for rooms, furniture, sports, and body height.
Everyday scale
Feet are natural for room dimensions, furniture, ceiling height, and short distances.
Height scale
Human height in US customary form is commonly written as feet plus inches.
Construction scale
Building materials, drawings, and field measurements in the US often use feet.
Foot vs meter
The foot is customary; the meter is SI and metric. One meter is about 3.280839895 feet, while one foot is exactly 0.3048 meters.
Common uses
- Human height and body measurements in US customary form.
- Room size, ceiling height, real estate, and construction dimensions.
- Sports fields, running distances, and elevation or altitude references.
- Furniture, lumber, cables, ladders, and household measurements.
How to measure in feet
Use a tape measure, ruler, measuring wheel, or laser distance tool. Read whole feet first, then remaining inches or decimal feet, and record the unit clearly.
- Start from the zero mark.
- Keep the tape straight along the measured line.
- Record leftover inches separately or convert them into decimal feet.
Conversion formulas
Foot conversion table
| Feet | Inches | Meters | Centimeters | Yards |
|---|---|---|---|---|
| 1 ft | 12 in | 0.3048 m | 30.48 cm | 0.3333333333 yd |
| 3 ft | 36 in | 0.9144 m | 91.44 cm | 1 yd |
| 5 ft | 60 in | 1.524 m | 152.4 cm | 1.666666667 yd |
| 10 ft | 120 in | 3.048 m | 304.8 cm | 3.333333333 yd |
Common mistakes
- Confusing foot marks and inch marks in notation such as 5' 10".
- Using 3 ft as if it were exactly 1 meter. It is only an estimate.
- Writing fts instead of ft.
- Mixing linear feet with square feet or cubic feet.
Related Xunits pages
Foot converters
Length references
FAQ
How many inches are in one foot?
One foot equals exactly 12 inches.
How many meters are in one foot?
One foot equals exactly 0.3048 meters.
What is the symbol for foot?
The standard symbol is ft.
Is foot metric?
No. The foot is imperial and US customary, though it has an exact metric value.
What is the difference between foot and feet?
Foot is singular; feet is plural. The symbol ft is used for both.