Fidamen

Convert Feet and Inches to Centimeters – Length Converter

This tool converts a length entered as feet and inches into centimetres using the international definition that 1 inch equals exactly 25.4 millimetres (2.54 centimetres). Enter whole or fractional inches; the converter treats feet and inches as a single linear measure before converting.

The result is appropriate for everyday use, engineering approximations, and documentation where a simple numeric centimetre value is required. For legal, calibration, or safety-critical measurements follow laboratory procedures and the referenced standards for measurement uncertainty and reporting.

Updated Nov 16, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 059c6f4f65b7 • Reviewed by Fidamen Standards Committee

Interactive converter unavailable for this calculator.

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Methodology

The converter applies the fixed, exact relationship defined by international standards: 1 inch = 25.4 mm exactly. Therefore all conversions are exact arithmetical operations based on that constant. This approach is consistent with guidance from national metrology institutes and SI conventions.

When high accuracy is required, account for measurement uncertainty (device resolution, operator error, environmental effects). For traceable or regulated measurements consult NIST, ISO, or the appropriate industry standard and document the measurement uncertainty and calibration status of instruments.

Key takeaways

Use the formula cm = (feet * 12 + inches) * 2.54 for exact arithmetic conversion.

For high-stakes or regulated measurements, combine this arithmetic conversion with calibrated instruments and documented uncertainty per NIST/ISO guidance.

Worked examples

5 ft 10 in → (5*12 + 10) = 70 in → 70 * 2.54 = 177.80 cm

6 ft 0 in → (6*12 + 0) = 72 in → 72 * 2.54 = 182.88 cm

0 ft 11.5 in → (0*12 + 11.5) = 11.5 in → 11.5 * 2.54 = 29.21 cm

F.A.Q.

Why does the converter use 2.54 as the inch-to-centimetre factor?

By international agreement and SI convention, 1 inch is defined as exactly 25.4 millimetres, which equals exactly 2.54 centimetres. This exact definition is used in metrology and standards publications.

Can I enter fractional inches (for example 5 ft 7 3/8 in)?

Yes. Enter fractional inches as a decimal (for example 7.375 for 7 3/8). The calculation uses the decimal value and applies the exact conversion factor.

What rounding or precision should I use for the result?

For general use two decimal places (0.01 cm) is common. For technical or regulatory work, follow the precision and uncertainty reporting required by your industry or laboratory, and retain extra significant figures internally until final reporting.

Is this suitable for legal measurements or medical records?

This converter provides arithmetic conversion only. For legal, medical, or regulated measurements, use calibrated instruments, follow documented measurement procedures, and record measurement uncertainty and instrument calibration status as required by governing standards.

How do I convert centimetres back to feet and inches?

To convert back, divide centimetres by 2.54 to get total inches, then integer-divide by 12 to get feet and take the remainder as inches. For example: total_inches = cm / 2.54; feet = floor(total_inches / 12); inches = total_inches - feet*12.

Sources & citations

Further resources

Versioning & Change Control

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

Record ID: 059c6f4f65b7

What changed (latest)

v1.0.0 • 2025-11-16 • 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

UI

v1.0.0

Governance

Last updated: Nov 16, 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 • 2025-11-16 • 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: e1fd5f5b42d0