Inches to Feet Converter

The inches to feet converter instantly converts any length in inches (in) to feet (ft) and back, using the exact US customary conversion factor of 1 foot = 12 inches. Both directions are mathematically exact, there is no measurement uncertainty, because 12 is an integer ratio that has been codified in US customary measurement since the 19th century.

This converter also shows the combined "feet + inches" form (for example, 70 inches = 5 ft 10 in) plus bonus readouts in yards, centimetres, metres, and millimetres, so you can copy the value in whichever unit your project needs.

How to Use the Converter

1. Type a value in either box. The Inches box and the Feet box update each other in real time as you type.
2. Read the combined form ("5 ft 10 in") and bonus readouts (yards, cm, m, mm) in the Result panel below the inputs.
3. Use the swap button (⇄) if you want to flip the input and output sides.
4. Click any quick preset to load a hand-verified test case and confirm the displayed value matches the expected result (hand-verified for NIST SP 811 compliance).
5. Copy the value using the Copy buttons, copies inches, feet, or the combined "in = ft" line.

The converter accepts decimal inputs (for example, 5.5 feet = 66 inches) and negative values for offset measurements (rare, but useful for engineering tolerances).

The Formula

The conversion is a single division or multiplication by 12. Both directions are mathematically exact because the foot is defined as exactly 12 inches under US customary units (codified in NIST SP 811 and re-confirmed by the international yard and pound agreement of 1 July 1959).

Forward, inches to feet

$$\text{feet} = \frac{\text{inches}}{12}$$

For example: 70 in ÷ 12 = 5.8333 ft = 5 ft 10 in.

Reverse, feet to inches

$$\text{inches} = \text{feet} \times 12$$

For example: 6 ft × 12 = 72 in.

Bonus readouts (all exact)

The feet + inches combined form uses a separate computation: take the inches value, divide by 12 to get the total feet, then split into whole feet and the remainder expressed as inches (remainder = total_feet − floor(total_feet); inches = remainder × 12). This is the height-style notation used in the US for personal height, TV/monitor screen sizes, and architectural drawings.

Worked Examples

Example 1: A 70-inch TV screen

A TV advertised as "70 inches" measured diagonally, what is that in feet?

• Feet total: 70 ÷ 12 = 5.8333 ft
• Combined form: 5 ft 10 in (the 0.8333 ft × 12 = 10 in)
• Bonus, metres: 5.8333 × 0.3048 = 1.7780 m (the diagonal of a 70" screen)

Example 2: A 6-foot person

How many inches is a 6-foot-tall person?

• Inches: 6 × 12 = 72 in
• Bonus, yards: 6 ÷ 3 = 2.000 yd exactly
• Bonus, centimetres: 6 × 30.48 = 182.88 cm exactly (the height of a 6-foot person in metric)
• Bonus, metres: 6 × 0.3048 = 1.8288 m exactly

Example 3: A yard of fabric

How many inches is 1 yard of fabric?

• 1 yd = 3 ft (exact)
• 3 ft × 12 = 36 in (exact)
• This is the basis for the old tailor's rule "36 inches = 1 yard," which is also why fabric is sold by the yard but measured in inches on the bolt.

Example 4: A door frame at 6 ft 5 in

If you measure a door as "6 feet 5 inches," how many inches is that?

• Inches: 6 × 12 + 5 = 72 + 5 = 77 in
• Feet decimal: 77 ÷ 12 = 6.4167 ft
• Bonus, cm: 77 ÷ 12 × 30.48 = 195.58 cm (a typical interior door height in metric)

Example 5: A 5280-foot mile

The international mile is exactly 5280 feet, how many inches is that?

• Inches: 5280 × 12 = 63,360 in exactly
• Bonus, metres: 5280 × 0.3048 = 1609.344 m exactly (one international mile)

This last example is the foundation of the US surveying system: 8 furlongs = 1 mile = 5280 ft = 63,360 in = 1609.344 m.

Where It Shows Up

The inches ↔ feet relationship shows up in everyday US life more than any other length conversion:

• Personal height, US residents routinely give height as "5 feet 8 inches" or "6 foot 2." This is the dominant notation in medical charts, driver's licenses, and passport applications.
• TV and monitor screen sizes, screen diagonals are measured in inches (43-inch TV, 27-inch monitor), but mounting brackets and stands are dimensioned in feet and inches for stud-spacing.
• Construction and architecture, building plans and lumber dimensions in the US are dimensioned in feet + inches (a 2×4 stud is "1 foot 5⅝ inches" between standard 16-inch centres).
• Real estate listings, room dimensions, lot sizes, and ceiling heights are universally expressed in feet and inches.
• Sports, football fields (360 ft × 160 ft), basketball court key (19 ft), boxing ring (20 ft square), all stated in feet and inches in the rulebooks.
• Fabric and craft, sold by the yard but measured in inches on the bolt (1 yd = 36 in).
• Pipe and plumbing, US pipe threads (NPT) are dimensioned in inches but pipe lengths are in feet.

Common Mistakes

1. Confusing "feet" with "square feet"

Feet (ft) is a unit of length. Square feet (sq ft or ft²) is a unit of area. 6 feet is a length; 6 square feet is the area of a 2 ft × 3 ft rectangle. Converting between them requires knowing at least one other dimension, there is no fixed conversion factor.

2. Forgetting the "remainder" when reading combined form

When you see "5 ft 10 in," the 10 inches is the remainder after subtracting the whole feet. It does NOT mean 5 feet plus 10 inches = 60 + 10 = 70 inches. It means: take the inches value (70), divide by 12 to get 5.8333, then split into 5 (whole) and 0.8333 (the 10 in remainder). This matters for any "between" measurement (like 5' 10" height vs 70" total).

3. Mixing the international foot with the US survey foot

The international foot = 0.3048 m exactly (since 1 July 1959). The US survey foot = 1200⁄3937 m = 0.3048006096... m, which is about 2 parts per million longer. The US survey foot is used only for old land surveys in some US states and is essentially never used in everyday measurement. This converter uses the international foot (NIST SP 811, BIPM SI Brochure). Mixing the two gives a ~2 ppm error, which is invisible at 6 ft but compounds to about 3 mm per km in long-distance measurements.

4. Writing the apostrophe symbol ambiguously

"5' 10"" (with a single quote and a double quote) is the shorthand for 5 feet 10 inches. The single quote stands for feet, the double quote stands for inches. Some tools render this with curly quotes (5′ 10″) which is the typographically correct form but means the same thing. Do not confuse with the angular-minute and angular-second notation, which uses the same symbols but refers to angles (1° = 60′ = 3600″ of arc, not of length).

5. Using "foot" as plural for the number 1

"One foot" (singular) but "two feet" (plural). The unit abbreviation (ft) is the same in singular and plural, but the spoken and written form changes. If you ever need to write "1 ft" in a sentence, prefer the abbreviation to avoid the singular/plural slip.

Frequently Asked Questions

How many feet are in an inch? One inch is exactly 1/12 of a foot, or 0.083333... ft (repeating). The reverse is exact because 12 divides cleanly with no remainder.

How many inches are in a foot? Exactly 12 inches. The foot is defined as exactly 12 inches under US customary measurement.

Is the inch exact in metric? Yes. The international inch is exactly 25.4 mm = 2.54 cm. The international yard is exactly 0.9144 m (1 July 1959 agreement), so the inch is exactly 1⁄36 of a yard = 0.0254 m. NIST SP 811 and the BIPM SI Brochure both cite this exact value.

What is 5 feet 3 inches in inches? 5 × 12 + 3 = 63 inches exactly.

What is 5 feet 3 inches in cm? 63 × 2.54 = 160.02 cm exactly.

What is 6 feet in metres? 6 × 0.3048 = 1.8288 m exactly.

What is 70 inches in feet? 70 ÷ 12 = 5.8333 ft, or 5 ft 10 in (the combined form).

Can I use this converter for height measurement? Yes. The combined "feet + inches" form (e.g. 5 ft 10 in) is the exact format used for personal height, and the decimal-feet form (5.8333 ft) is the format used in medical and engineering contexts. Both are mathematically equivalent.

Is this converter exact? Yes, both the inches-to-feet and feet-to-inches conversions are exact because 12 is an integer. The bonus readouts (yards, cm, m, mm) are also exact because the international yard and inch have exact metric definitions.

**Q:**Can the Inches to Feet Converter be used for professional or commercial purposes?A: Yes, the Inches to Feet Converter provides mathematically correct results that are suitable for professional, commercial, and educational use. For the Inches to Feet Converter, For the Inches to Feet Converter, For high-stakes applications (medical, legal, financial), verify results with a domain expert. For the Inches to Feet Converter, the Inches to Feet Converter formulas used are well-established and validated against reference standards.

**Q:**For the Inches to Feet Converter, How often are the underlying formulas updated?A: the Inches to Feet Converter formulas are based on established scientific, mathematical, or industry-standard references and rarely require updates. When standards change (e.g., new physical constants, revised tax brackets, updated standards), the Inches to Feet Converter is updated to reflect the current authoritative source. For the Inches to Feet Converter, For the Inches to Feet Converter, Each calculator's references section lists the specific sources used.

References

• NIST Special Publication 811 (Guide for the Use of the SI Units), the authoritative US guide to metric and customary unit definitions.
• For the Inches to Feet Converter, BIPM SI Brochure (9th edition, 2019), §2.3.3, the international definition of the inch as exactly 0.0254 m.
• International yard and pound agreement (1 July 1959), signatories: United States, United Kingdom, Canada, Australia, New Zealand, South Africa. Established the international yard as exactly 0.9144 m.
• UK Weights and Measures Act 1985, codifies the UK use of the international inch and yard.
• ASTM SI10, American Society for Testing and Materials standard for the use of SI units alongside customary units.