1 Foot to Meters

One foot is 0.3048 meters, exactly

One foot is 0.3048 meters, exactly. There is no rounding in that figure: the international foot was fixed at 0.3048 m when the yard was set to 0.9144 m in 1959, and a foot is one third of a yard. NIST's Guide to the SI, Appendix B (2008) prints 3.048 E-01 m in bold, which is how it marks an exact factor, and the BIPM SI brochure, 9th edition (2019), defines the meter itself from the speed of light, so both sides of the ratio are fixed.

The same foot is 30.48 cm, 304.8 mm, 12 in, 0.333333 yd and 0.0003048 km. Every one of those figures is exact, because the inch is exactly 0.0254 m and the yard is exactly 3 ft: 12 x 0.0254 = 0.3048, and 0.3048 x 3 = 0.9144.

The miles row is the one people forget. A mile is 5,280 ft, so one foot is 1/5,280 of a mile, and 5,280 x 0.3048 = 1,609.344 m. That is the number behind the 1.609 km mile marker on every US highway sign.

Half a foot, a quarter foot and dressed lumber

Half a foot is 6 in, which is 0.1524 m, and a quarter foot is 3 in, or 0.0762 m. Those two fractions cover most of the small measurements a tape measure produces, because US tape measures divide the foot into 12 inches and then into halves, quarters, eighths and sixteenths.

Lumber is where the fractions bite. A board sold as a 2x4 is 1.5 in by 3.5 in dressed, which is 38.1 mm by 88.9 mm, and a 2x6 is 1.5 in by 5.5 in, or 38.1 mm by 139.7 mm. The length is the part that stays honest: an 8 ft stud is 2.4384 m, a 10 ft board is 3.048 m and a 12 ft board is 3.6576 m.

A metric tape and a US tape read the same object in different units, and the 1.5 in width of a dressed 2x4 is the classic mismatch. A plan drawn in millimeters asks for 38 mm stock, and the 38.1 mm board on the rack is 0.1 mm wider, which is 0.004 in and well inside any saw cut.

Square feet and cubic feet from the same number

Area and volume start from the same 0.3048. One square foot is 0.3048 x 0.3048 = 0.09290304 m², and one cubic foot is 0.3048 cubed, which is 0.028316846592 m³.

A 10 ft by 12 ft room is 120 sq ft, which is 11.1484 m², and the same room in a European listing is advertised as 11.15 m². A 12 ft by 12 ft deck is 144 sq ft, or 13.3780 m², and a 20 ft by 20 ft garage slab is 400 sq ft, or 37.1612 m².

Volume runs the same way. A 20 ft shipping container holds about 1,172 cu ft, which is 33.2 m³, and a refrigerator listed at 25 cu ft is 0.7079 m³. Concrete sold by the cubic yard is the one order that has to be right: 27 cu ft is 1 cu yd and 0.7646 m³, so a slab 10 ft x 10 ft x 4 in takes 33.33 cu ft, or 1.23 cu yd, which is 0.944 m³.

The gallons row is worth remembering for tanks. One cubic foot holds 7.480519 US gallons, so a 55 gallon drum is 7.35 cu ft, and a 100 gallon tank is 13.37 cu ft.

One foot of pipe, hose and cable

Short lengths are where a single foot turns into a purchase. Cable, hose, pipe and trim are all sold by the foot in the US and by the meter almost everywhere else, and the conversion is the same 0.3048 with the decimal moved.

The round numbers in that table are not accidents. Twenty-five feet is 7.62 m, fifty is 15.24 m and a hundred is 30.48 m, so an extension cord sold in the US as 100 ft is a 30 m cord in a European catalog, with 48 cm to spare. A 250 ft spool of cable is 76.2 m, and a 1,000 ft reel is 304.8 m, which is the figure a contractor needs when the spec sheet is metric.

Pipe is the case where the label lies. A 1 in pipe does not measure 1 in across, and its length is still sold by the foot: a 10 ft stick is 3.048 m and a 21 ft stick is 6.4008 m. Threads are cut in inches on US pipe, so a metric drawing that calls for a 3 m length has to be cut from a 10 ft stick with 48 mm trimmed off.

Hose is sold in the same 25 ft and 50 ft lengths, and a 50 ft garden hose at 15.24 m is close enough to a 15 m hose that the nozzle fits either way.

Reading meters back into feet

Going the other way, one meter is 3.280839895 ft, or 3 ft 3.37 in. The repeating decimal is why metric drawings and US tape measures never fully agree.

Two rows in that table explain a lot of confusion. A 1.8 m doorway is 5 ft 10.87 in, which is a standard 6 ft 8 in opening once the frame is counted, and a 2 m counter is 6 ft 6.74 in, which is why a US kitchen drawn at 6 ft 6 in reads as 1.9812 m on a metric plan.

The 3 m row is the one that catches importers. Three meters is 9 ft 10.11 in, so a 10 ft US product is 3.048 m and a 3 m metric product is 9.84 ft. The two look the same on a spec sheet and differ by 48 mm, which is enough to fail a fit check on a shelf or a door frame.

For a quick mental estimate, multiply meters by 3.3 and accept a small overshoot. A 2 m length reads 6.6 ft against a true 6.5617, which is 0.038 ft, or about a half inch, over on a 6 ft 7 in object.

Feet and inches on a tape measure

A height written as 5'6" is 5 ft plus 6 in, and the metric version needs both parts converted. Five feet is 1.524 m and 6 in is 0.1524 m, so 5'6" is 1.6764 m.

The inches column is the shortcut. Multiply total inches by 0.0254 and the meters appear directly, so 66 in is 1.6764 m and 74 in is 1.8796 m. A passport form or a medical chart that asks for centimeters wants the last column, and 5'6" becomes 167.64 cm rather than 168.

Rounding a height to the nearest centimeter is safe for a form and risky for a doorway. A 6 ft 8 in door is 80 in, or 2.032 m, and a 2.03 m metric door is 79.92 in, which is 2 mm short of the US opening. That gap matters when a prehung frame is ordered from a metric catalog.

The same arithmetic handles a person's reach, a shelf height or a basketball rim. Ten feet is 3.048 m, and a rim set at 3.05 m is 10.0066 ft, which is 2 mm high and inside any tolerance a gym cares about.

Why the survey foot still shows up on old deeds

Until the end of 2022 there were two legal feet in the US. The international foot is 0.3048 m exactly, and the U.S. survey foot is 1200/3937 m, which is 0.3048006096 m, about two parts per million longer.

That tiny gap adds up over survey distances, and it is why old deeds and state plane coordinates carry a different number. Over one mile the survey foot gives 5,280 x 0.3048006096 = 1,609.3472 m against 1,609.344 m for the international foot, a difference of 3.2 mm. Over a 10 mile boundary the gap is 32 mm, which is enough to move a fence line on paper.

NIST's page on the U.S. survey foot records the schedule: December 31, 2022 was the last day it should be used, and from January 1, 2023 the international foot at 0.3048 m exactly supersedes it for all applications. The NIST and NOAA notice on retiring the survey foot notes that legacy state plane systems still carry it for historic work.

For anything a homeowner measures, the two feet are the same. A 100 ft lot line differs by 0.06 mm between the definitions, and a tape measure sold today is stamped to the international foot. The distinction only matters when a document written before 2023 is being converted, and then the right move is to use 1200/3937 rather than 0.3048 and say which one was used.

That is the whole story of the foot in one line: 0.3048 m exactly for everything built since 1959 and legally for everything since 2023, with a surveyor's variant that survives in old records and in the state plane systems that NOAA still supports.