Convert Kilometers to Feet – Length Converter

This converter transforms a length given in kilometers (km) to feet (ft) using the standard international relationship between the metre and the foot. It is intended for everyday conversions, engineering estimates, and documentation where the international foot (1 ft = 0.3048 m exactly) is appropriate.

For high-precision surveying or legacy data that use the US survey foot, see the methodology and FAQs for guidance on differences. The tool reports mathematical conversion; measurement uncertainty from instruments or geodetic calculations is not included.

Updated Nov 3, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 04b03af3af04 • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between kilometer and foot with precision rounding.

Kilometer (km)Foot (ft)

Quick reference table

Kilometer	Foot
1 km	3,280.8399 ft
5 km	16,404.1995 ft
10 km	32,808.399 ft
25 km	82,020.9974 ft
50 km	164,041.9948 ft
100 km	328,083.9895 ft

Methodology

The conversion uses the International System of Units (SI) definition of the metre and the internationally agreed definition of the foot as exactly 0.3048 metres. Therefore 1 kilometre (1000 metres) equals 1000 / 0.3048 feet.

Where required for regulatory or technical work, users should verify which 'foot' definition is mandated (international foot vs US survey foot). For numerical display this tool follows standard IEEE floating-point rules for rounding when formatting output.

Worked examples

1 km = 3,280.8398950131 ft (using international foot).

0.5 km = 1,640.4199475066 ft.

5 km = 16,404.1994775656 ft.

F.A.Q.

What exact conversion factor does this tool use?

This tool uses the international foot defined as exactly 0.3048 metres. That yields 1 kilometre = 1000 / 0.3048 = 3,280.839895013123... feet (displayed rounded).

Is there more than one definition of a foot?

Yes. The international foot (1 ft = 0.3048 m) is standard for most applications. The US survey foot is a slightly different exact value used historically in surveying. Use the US survey foot only when required by geodetic or legacy surveying specifications.

How many significant digits should I trust in the result?

Mathematically the conversion factor is exact given the definitions used. Practical trust in digits depends on input measurement accuracy and instrument uncertainty. For engineering documents, match digits to measurement uncertainty; for simple arithmetic, 4–6 significant digits are usually sufficient.

Does this conversion account for geographic or geodesic distance?

No. This is a unit conversion of scalar lengths. Converting coordinates or measuring great-circle/geodetic distances requires geodesy methods and ellipsoid models (not covered by this unit converter).

Why might displayed results differ slightly between tools?

Differences arise from (1) which foot definition is used, (2) rounding or decimal formatting, and (3) floating-point representation and rounding behavior per IEEE 754. This tool uses the international foot and rounds display output for readability.

Sources & citations

NIST Special Publication 811, Guide for the Use of the International System of Units (SI) — https://www.nist.gov/pml/special-publication-811
ISO - Quantities and units (ISO 80000 series overview) — https://www.iso.org/standard/30669.html
IEEE Standard for Floating-Point Arithmetic (IEEE 754) — https://standards.ieee.org/standard/754-2019.html
NIST note on the international foot and US survey foot — https://www.nist.gov/pml/us-survey-foot

Further resources

Related tools

External guidance

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 04b03af3af04

What changed (latest)

v1.0.0 • 2025-11-03 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

Governance

Last updated: Nov 3, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
MINOR: New features or fields that do not change existing outputs for the same inputs.
PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

Verify formulas and unit definitions against primary standards or datasets.
Run golden-case regression suite and edge-case suite.
Record reviewer sign-off with credentials and scope.
Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

Uses exact unit definitions from the Fidamen conversion library.
Internal calculations use double precision; display rounding follows the unit's configured decimal places.
Not a substitute for calibrated instruments in regulated contexts.
Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-03 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 4b7d2206665b