Feet to Inches Converter

The foot-inch relationship predates the metric system by centuries — the inch was originally about the width of a thumb and the foot roughly the length of a human foot, and by the time these were standardized in medieval England the foot was fixed at 12 inches, echoing the Roman duodecimal system. Today both units are legally defined in terms of the meter (1 in = 25.4 mm exactly, so 1 ft = 0.3048 m), but the 12:1 ratio between foot and inch itself never changed.

No — since 1 foot is defined as exactly 12 inches, multiplying by 12 never introduces rounding error the way cm-to-inch conversion (dividing by 2.54) does. Any feet value with a terminating decimal — 5.5, 6.25, 0.75 — converts to a terminating inch value (66, 75, 9) with no repeating decimals, so this converter always returns an exact figure, no matter how large or small the input.

Multiply the whole-foot part by 12 and add the leftover inches: 5 ft 6 in = (5 × 12) + 6 = 66 inches. This is the standard method for converting US height measurements, shoe-rack or closet dimensions, or lumber lengths given in feet-and-inches notation into a single inch figure for calculations, spreadsheets, or CAD software that expects one unit.

Tape measures and blueprints are graduated in fractions — typically 1/16 or 1/32 inch — and a carpenter marking a cut rounds to the nearest visible line on the tape. This converter, by contrast, computes the mathematically exact result of multiplying feet by 12, with no rounding at all. For example, 7.083 feet (7 feet 1 inch) converts to precisely 85 inches, but a framer eyeballing that same length on a tape measure might mark it a hair off due to the tool's resolution. The mismatch comes from measurement-tool precision, not from any imprecision in the ft-to-in factor itself, which is always exactly ×12 regardless of input size. When accuracy matters, enter feet as a decimal (or feet plus inches divided by 12) rather than eyeballing a fraction on a tape.

Almost, but not quite. This converter uses the international foot, fixed since 1959 at exactly 0.3048 meters (so 1 ft = 12 in exactly). Land surveyors historically used a slightly different "US survey foot," defined as 1200/3937 meters — about 0.3048006 meters, roughly two parts per million longer. Over a mile (5,280 feet), that tiny gap accumulates to about 0.13 inches, negligible for everyday carpentry but material in large-scale land surveys and legal property boundary descriptions written decades ago. The US officially retired the survey foot at the end of 2022 in favor of the international foot for all federal purposes, so today this conversion applies uniformly with no distinction between the two — you'd only encounter the older definition when reading a pre-2023 deed or survey plat.

Add up the four wall lengths in feet first, then convert the total to inches: perimeter = 2 × (12 + 10) = 44 feet, and 44 × 12 = 528 inches of baseboard or crown molding needed before subtracting door openings and closets. Contractors typically work in feet for room dimensions on a floor plan but need inches for cutting trim to length, checking miter angles, or ordering molding sold by the linear foot or inch. Converting the full perimeter in one step, rather than converting and re-adding each wall separately, avoids compounding small rounding errors across multiple additions, and makes it easy to estimate how many 96-inch (8-foot) trim boards the job will need, and how much to add for waste on mitered corners.

The split predates the metric system by roughly 1,700 years. The Romans divided their standard length unit, the pes (Roman foot), into 12 equal parts called unciae — the same root word that eventually gave English both "inch" and "ounce." When the English foot was later standardized, it kept this Roman duodecimal (base-12) structure rather than switching to a base-10 division. Twelve has a practical advantage over ten for tradespeople: it divides evenly by 2, 3, 4, and 6, making it far easier to split a length into thirds or quarters without landing on an awkward fraction — the same reason a dozen, a clock face, and 12 inches all share that base, a convenience that mattered a great deal before calculators existed.

No — that shortcut only works for a single linear dimension, not area. Area scales with the square of the length factor, so 1 square foot equals 144 square inches (12 × 12), not 12. A 10-square-foot countertop, for instance, is 1,440 square inches, not 120. The same logic compounds further for volume: 1 cubic foot equals 1,728 cubic inches (12 × 12 × 12), which is why shipping and storage specs in cubic feet look so much larger once converted to cubic inches. This tool converts linear feet to linear inches only — for area, multiply the square-foot value by 144; for volume, multiply cubic feet by 1,728. Mixing these up is a common estimating mistake when ordering flooring, paint, or concrete by the square or cubic foot and then trying to cross-check the figure against a spec sheet listed in inches.