Feet to Picometers (ft to pm)

1 foot equals 304,800,000,000 picometers exactly.

1 foot = 304,800,000,000 picometers

How to convert feet to picometers

To convert feet to picometers, multiply the number of feet by 304,800,000,000. This factor is exact. To go the other way, multiply picometers by 3.280839895×10⁻¹² (rounded).

picometers = feet × 304,800,000,000

Example: 10 feet = 3,048,000,000,000 picometers.

About these units

Foot (ft)

US & ImperialCurrent unit

12 inches. Defined as exactly 0.3048 meters. Still the standard unit for height, altitude in aviation and room dimensions in the US and UK.

Human anatomy supplied the idea: an adult foot is roughly 15 percent of body height. Ancient cultures turned that into standards, but not the same one. The Greek pous was about 302 mm, the standard Roman pes about 295.7 mm, and a Harappan foot of about 335 mm has been reported from the Indus Valley. Historically, a foot fell somewhere between about 250 and 335 mm. Charlemagne tried to standardize units around 790 with little lasting success, and in 1593 English law fixed the statute mile at 5,280 feet.

The modern foot dates from the 1959 International Yard and Pound Agreement, which defined the yard as exactly 0.9144 meter and so the foot as exactly 0.3048 meter; the UK adopted it on 1 January 1964. The US survey foot, defined in 1893 as 1200/3937 meter, was deprecated on 31 December 2022. Feet remain in everyday use for height and rooms in the US, and ISO shipping containers are defined in them. Aviation altitudes use them too: flight level 330 means 33,000 feet.

1 foot = 0.3048 meters (exactly).

Sources: Wikipedia: Foot (unit); Wikipedia: Mile; NIST Guide to the SI, Appendix B.8: conversion factors

Picometer (pm)

Metric (SI)Current unit

One trillionth of a meter. Atomic diameters are typically a few hundred pm.

One trillionth of a meter, the picometer (pm) is the SI length that sits below the nanometer and above the femtometer. It equals 0.01 angstrom, so a figure in angstroms converts by multiplying by 100. Wikipedia notes that the symbol mu-mu was once used for it, and the NIST list of SI prefixes gives pico as 10 to the power of minus 12.

In practice the unit belongs to chemistry and atomic physics, where distances between bonded atoms are expressed as a few hundred of them. A carbon to carbon single bond is about 154 pm long, and a helium atom is estimated at about 62 pm across, while atoms in general run from roughly 62 to 520 pm in diameter. Chemists who grew up with the angstrom increasingly quote the same distances in picometers, because the angstrom is no longer part of the SI. Gravitational-wave work pushes the scale further: the planned LISA detector is expected to resolve displacements of about 20 pm over a 2.5 million kilometer baseline.

1 picometer = 1×10⁻¹² meters (exactly).

Sources: Wikipedia: Picometre; NIST: metric (SI) prefixes; Wikipedia: Angstrom

Related conversions

See all length units.