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Sources and Accuracy
Length conversions use the metre as the reference unit. Common imperial relationships are exact where standardized, such as 1 inch = 0.0254 metre and 1 foot = 0.3048 metre.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-05-21.
About These Units
picometer [pm]
Definition
The picometer (pm) is a length unit used to express measurements in this converter.
History
This unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current use
Use picometer when comparing length values, checking specifications, converting between systems, or preparing quick estimates.
foot [ft]
Definition
The foot is an imperial and US customary length unit equal to exactly 12 inches or 0.3048 meters.
History
Foot-based measurement has long customary roots and was standardized internationally in the modern yard-pound system.
Current use
Feet are common in building plans, room sizes, height measurements, aviation altitude, and real estate.