Convert Pounds to Ounces – Weight Converter
This tool converts pounds (lb) to ounces (oz) using the standard avoirdupois system where 1 pound equals 16 ounces. Enter a single numeric value in pounds to get the equivalent number of ounces.
The converter is intended for everyday use, recipe scaling, shipping calculations, and basic engineering checks. It includes clear notes on precision, calibration, and situations where alternate units (for example troy ounces) are required.
Governance
Record 30cf3d1e388a • Reviewed by Fidamen Standards Committee
Interactive converter unavailable for this calculator.
We could not resolve compatible units for this experience. Please verify the slug follows the pattern `from-unit-to-unit-converter`.
Methodology
The conversion uses a fixed mathematical relationship from the avoirdupois system: 1 pound = 16 ounces exactly. This relationship is a defined unit ratio and does not vary.
For measurement best practices and declared accuracy, follow calibration and uncertainty guidance from national metrology organizations. Recommended references include national measurement institute guidance on unit definitions and calibration traceability.
When entering measured values, account for scale resolution and calibration status. Report results with a number of significant figures consistent with the input measurement uncertainty; do not imply greater accuracy than the measurement permits.
Worked examples
2 lb → 2 × 16 = 32 oz
0.25 lb → 0.25 × 16 = 4 oz
3 lb 6 oz (convert mixed input): 3 + 6/16 = 3.375 lb → 3.375 × 16 = 54 oz
F.A.Q.
Does this conversion use troy ounces or avoirdupois ounces?
This converter uses the avoirdupois ounce (1 oz = 28.349523125 g) and standard avoirdupois pound (1 lb = 16 oz). Troy ounces, used for precious metals, are different and are not used here.
How many significant figures will the result show?
The calculator returns numeric results without implying measurement uncertainty. For reporting, round results to match the input measurement's significant figures or the resolution of your scale. If your scale reads to the nearest 0.1 lb, report converted ounces to comparable precision.
Can I convert fractional pounds (for example 5.25 lb)?
Yes. Convert the decimal pounds directly by multiplying by 16. Example: 5.25 lb × 16 = 84 oz.
What about calibration and accuracy?
For tasks requiring traceable accuracy (commercial weighing, lab work, legal-for-trade), ensure your scale is calibrated against standards traceable to a national metrology institute and follow published calibration intervals and uncertainty reporting (see cited metrology guidance).
Is there any situation where the conversion factor of 16 would not apply?
The factor 16 applies for the avoirdupois system. It does not apply to systems using different ounce definitions (for example troy ounce). For all standard everyday weight conversions between pounds and ounces, 16 is exact.
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
- International Bureau of Weights and Measures (BIPM) - SI Brochure and unit definitions — https://www.bipm.org
- Occupational Safety and Health Administration (OSHA) - Workplace measurement and calibration guidance — https://www.osha.gov
- National metrology institute calibration guidance — https://www.nist.gov/pml/calibration
- ISO 80000-5:2019 — Thermodynamics — https://www.iso.org/standard/64976.html
- NIST SP 330 — The International System of Units (SI) — https://www.nist.gov/pml/special-publication-330
- BIPM SI Brochure (9th edition, 2019) — https://www.bipm.org/en/publications/si-brochure
Further resources
Related tools
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 30cf3d1e388aWhat 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
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
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: 42b2ea1486d2