Meters to feet (m to ft)

One meter is exactly 3.280839895 feet. That is a definition rather than a measurement: the imperial and US customary units were fixed against metric ones by the 1959 international yard and pound agreement, so this factor does not drift and will not be revised.

Worked through: 10 m x 3.2808399 = 32.8084 ft.

Going the other way, one foot is 0.3048 meters.

For mental arithmetic: Multiply by 3 and add 10%. 10 m is 30 plus 3, so 33 feet; the true answer is 32.8.

Ceiling heights, room dimensions and swimming pools. Worth remembering that a meter is a little over three feet and NOT three feet exactly. The 9.4% gap compounds fast over a building, where assuming 3 puts a 30 meter frontage out by nearly nine feet.

Precision is worth matching to the input. A measurement given as 1 m carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.